Recent changes¶
Version 8.18¶
Summary of changes¶
Coq version 8.18 integrates two soundness fixes to the Coq kernel along with a host of improvements. We highlight a few impactful changes:
the default locality of
Hint
andInstance
commands was switched toexport
.the universe unification algorithm can now delay the commitment to a sort (the algorithm used to pick
Type
). Thanks to this feature manyProp
andSProp
annotations can be now omitted.Ltac2 supports array literals, maps and sets of primitive datatypes such as names (of constants, inductive types, etc) and fine-grained control over profiling.
The warning system offers new categories, enabling finer (de)activation of specific warnings. This should be particularly useful to handle deprecations.
Many new lemmas useful for teaching analysis with Coq are now part of the standard library about real numbers.
The
#[deprecated]
attribute can now be applied to definitions.
The 41 contributors to the 8.18 version are: Reynald Affeldt, Tanaka Akira, Matthieu Baty, Yves Bertot, Lasse Blaauwbroek, Ana Borges, Kate Deplaix, Ali Caglayan, Cyril Cohen, Maxime Dénès, Andrej Dudenhefner, Andres Erbsen, Jim Fehrle, Yannick Forster, Paolo G. Giarrusso, Gaëtan Gilbert, Jason Gross, Samuel Gruetter, Stefan Haan, Hugo Herbelin, Yoshihiro Imai, Emilio Jesús Gallego Arias, Olivier Laurent, Meven Lennon-Bertrand, Rodolphe Lepigre, Yishuai Li, Guillaume Melquiond, Karl Palmskog, Pierre-Marie Pédrot, Stefan Radziuk, Ramkumar Ramachandra, Pierre Rousselin, Pierre Roux, Julin Shaji, Kazuhiko Sakaguchi, Weng Shiwei, Michael Soegtrop, Matthieu Sozeau, Enrico Tassi, Hao Yang, Théo Zimmermann.
We are very grateful to the Coq community for their help in creating 8.18 in the 6 months since the release of Coq 8.17.0. Maxime Dénès and Enrico Tassi were the release managers.
Changes in 8.18.0¶
Kernel¶
Changed: the
bad-relevance
warning is now an error by default (#17172, by Pierre-Marie Pédrot).Fixed: the kernel now checks that case elimination of private inductive types (cf
private(matching)
) is not used outside their defining module. Previously this was only checked in elaboration and the check could be avoided through some tactics, breaking consistency in the presence of axioms which rely on the elimination restriction to be consistent (#17452, fixes #9608, by Gaëtan Gilbert).Fixed: a bug enabling
native_compute
to yield arbitrary floating-point values (#17872, fixes #17871, by Guillaume Melquiond and Pierre Roux, bug found by Jason Gross).
Specification language, type inference¶
Changed: enhance the universe unification algorithm, which is now able to delay the definition of a sort. This allows omitting some explicit
Prop
andSProp
annotations when writing terms. Some minor backwards compatibility issues can arise in rare cases, which can be solved with more explicit sort annotations (#16903, by Pierre-Marie Pédrot).Changed: match compilation for primitive record avoids producing an encoding overhead for matches that are equivalent to a primitive projection (#17008, by Gaëtan Gilbert).
Added: volatile casts
term :> type
which do not leave a trace in the elaborated term. They are used byPrinting Match All Subterms
to display otherwise hidden subterms of match constructs (#16992, fixes #16918, by Gaëtan Gilbert).Added: when printing uninterpreted terms (for instance through
Print Ltac
onLtac foo := exact some_term
), extensions to the term language (for instance Solving existential variables using tactics) are now printed correctly instead of as holes (_
) (#17221, by Gaëtan Gilbert).Added: Support for the
local
,global
andexport
locality attributes for the single "field" of definitional typeclasses when using the:>
and::
syntaxes for coercion and substructures (#17754, fixes #17451, by Pierre Roux).Added: a hook in the coercion mechanism to enable programming coercions in external metalanguages such as Ltac, Ltac2, Elpi or OCaml plugins (#17794, by Pierre Roux).
Fixed: canonical instance matching
match
terms (#17206, fixes #17079, by Gaëtan Gilbert).Fixed: universe constraint inference in module subtyping can trigger constant unfoldings (#17305, fixes #17303, by Gaëtan Gilbert).
Notations¶
Removed: The
'[='
keyword.'[='
tokens in notation definitions should be replaced with the pair of tokens'[' '='
. If compatibility with Coq < 8.18 is needed, replace[=
in uses of the notation with an added space ([ =
) (#16788, fixes #16785, by Pierre Roux).Added: Support for
Printing Parentheses
in custom notations (#17117, by Hugo Herbelin).Added: Improve printing of reverse coercions. When a term
x
is elaborated tox'
through a reverse coercion, return the termreverse_coercion x' x
that is convertible tox'
but displayedx
thanks to the coercionreverse_coercion
(#17484, by Pierre Roux).Fixed: Add support to parse a recursive pattern as a sequence of terms in a recursive notation even when this recursive pattern is used in position of binders; it was formerly raising an anomaly (#16937, fixes #12467, by Hugo Herbelin).
Fixed: Improved ability to print notations involving anonymous binders (#17050, by Hugo Herbelin).
Fixed: anomaly with notations abbreviating a local variable or record field name (#17217, fixes #14975, by Hugo Herbelin).
Fixed: Ensure in all cases that a parsing rule is declared when the
only parsing
flag is given (#17318, fixes #17316, by Hugo Herbelin).Fixed: In
Number Notation
, "abstract after N" was applied when number >= N. Now it is applied when number > N (#17478, by Jim Fehrle).
Tactics¶
Changed: in the fringe case where the
with
clause of a call tospecialize
depends on a variable bound in the type, the tactic will now fail instead of silently producing a shelved evar (#17322, by Pierre-Marie Pédrot).Changed: extensions to the term syntax through generic arguments (typically
ltac:()
,ltac2:()
or ltac2's$
) produce errors when used in term patterns (for instance patterns used to filter hints) instead of being treated as holes (_
) (#17352, by Gaëtan Gilbert).Changed: the
case
tactic and its variants always generate a pattern-matching node, regardless of their argument. In particular, they are now guaranteed to generate as many goals as there are constructors in the inductive type. Previously, they used to reduce to the corresponding branch when the argument βι-normalized to a constructor, resulting in a single goal (#17541, by Pierre-Marie Pédrot).Changed:
injection
continues working using sigma types whenEqdep_dec
has not been required even if an equality scheme was found, instead of failing (#17670, by Gaëtan Gilbert).Changed: the unification heuristics for implicit arguments of the
case
tactic. We unconditionally recommend usingdestruct
instead, and even more so in case of incompatibility (#17564, by Pierre-Marie Pédrot).Removed: the no-argument form of the
instantiate
tactic, deprecated since 8.16 (#16910, by Pierre-Marie Pédrot).Removed: undocumented tactics
hresolve_core
andhget_evar
(#17035, by Gaëtan Gilbert).Deprecated: the
elimtype
andcasetype
tactics (#16904, by Pierre-Marie Pédrot).Deprecated:
revert dependent
, which is a misleadingly named alias ofgeneralize dependent
(#17669, by Gaëtan Gilbert).Fixed: The
simpl
tactic now respects thesimpl never
flag even when the subject function is referred to through another definition (#13448, fixes #13428, by Yves Bertot).Fixed: unification is less sensitive to whether a subterm is an indirection through a defined existential variable or a direct term node. This results in less constant unfoldings in rare cases (#16960, by Gaëtan Gilbert).
Fixed: untypable proof states generated by setoid_rewrite, which may cause some backwards-incompatibilities (#17304, fixes #17295, by Lasse Blaauwbroek).
Fixed: intropatterns destructing a term whose type is a product cannot silently create shelved evars anymore. Instead, it fails with an unsolvable variable. This can be fixed in a backwards compatible way by using the e-variant of the parent tactic (#17564, by Pierre-Marie Pédrot).
Fixed: the
field_simplify
tactic, so that it no longer introduces side-conditions when working on a hypothesis (#17591, by Guillaume Melquiond).Fixed: the
tauto
tactic and its variants now try to match types up to universe unification. This makes them compatible with universe-polymorphic code (#8905, fixes #4721 and #5351, by Pierre-Marie Pédrot).
Ltac2 language¶
Added: Support for parsing Ltac2 array literals
[| ... |]
(#16859, fixes #13976, by Samuel Gruetter).Added: Finite set and map APIs for identifier, string, int, constant, inductive and constructor keys (#17347, c.f. #16409, by Gaëtan Gilbert).
Added: Ltac2 preterm antiquotation
$preterm:
(#17359, fixes #13977, by Gaëtan Gilbert).Added:
Ltac Profiling
also profiles Ltac2 tactics. Ltac2 also provides tacticsstart_profiling
stop_profiling
andshow_profile
for finer grained control (#17371, fixes #10111, by Gaëtan Gilbert).Added: primitives to build and compare values in
Ltac2.Init.cast
(#17468, by Gaëtan Gilbert).Added: It is possible to define 0-argument externals (#17475, by Gaëtan Gilbert).
Added: Ltac2 quotations ltac2val:(ltac2 tactic) in Ltac1 which produce Ltac1 values (as opposed to
ltac2:()
quotations which are only useful for their side effects) (#17575, by Gaëtan Gilbert).Fixed: nested notations involving Term Antiquotations (#17232, fixes #15864, by Gaëtan Gilbert).
Fixed: Parsing level of
by
clause of Ltac2'sassert
(#17508, fixes #17491, by Samuel Gruetter).Fixed:
multi_match!
,multi_match! goal
and the underlyingLtac2.Pattern.multi_match0
andLtac2.Pattern.multi_goal_match0
now preserve exceptions from backtracking after a branch succeeded instead of replacing them withMatch_failure
(e.g.multi_match! constr:(tt) with tt => () end; Control.zero Not_found
now fails withNot_found
instead ofMatch_failure
) (#17597, fixes #17594, by Gaëtan Gilbert).
Commands and options¶
Changed: the default locality of
Hint
andInstance
commands was switched toexport
(#16258, by Pierre-Marie Pédrot).Changed: warning
non-primitive-record
is now in categoryrecords
instead ofrecord
. This was the only use ofrecord
but the plural version is also used bycannot-define-projection
future-coercion-class-constructor
andfuture-coercion-class-field
. (#16989, by Gaëtan Gilbert).Changed:
Eval
prints information about existential variables likeCheck
(#17274, by Gaëtan Gilbert).Changed: The names of deprecation warnings now depend on the version in which they were introduced, using their "since" field. This enables deprecation warnings to be selectively enabled, disabled, or treated as an error, according to the version number provided in the
deprecated
attribute (#17489, fixes #16287, by Pierre Roux, reviewed by Ali Caglayan, Théo Zimmermann and Gaëtan Gilbert).Changed: warnings can now have multiple categories allowing for finer user control on which warning to enable, disable or treat as an error (#17585, by Gaëtan Gilbert).
Changed:
Template polymorphic
inductive types are not implicitly added to theKeep Equalities
table anymore when defined. This may change the behavior of equality-related tactics on such types (#17718, by Pierre-Marie Pédrot).Changed:
Warnings
andwarnings
now emit a warning when trying to enable an unknown warning (there is still no warning when disabling an unknown warning as this behavior is useful for compatibility, or when enabling an unknown warning through the command line-w
as the warning may be in a yet to be loaded plugin) (#17747, by Gaëtan Gilbert).Removed: the flag
Apply With Renaming
which was deprecated since 8.15 (#16909, by Pierre-Marie Pédrot).Removed: the
Typeclasses Filtered Unification
flag, deprecated since 8.16 (#16911, by Pierre-Marie Pédrot).Removed:
program
attribute is not accepted anymore with commandsAdd Relation
,Add Parametric Relation
,Add Setoid
,Add Parametric Setoid
,Add Morphism
,Add Parametric Morphism
,Declare Morphism
. Previously, it was accepted but ignored (#17042, by Théo Zimmermann).Removed: the
Elaboration StrictProp Cumulativity
andCumulative SProp
flags. These flags became counterproductive after the introduction of sort variables in unification (#17114, fixes #17108, by Pierre-Marie Pédrot).Removed: The
Add LoadPath
,Add Rec LoadPath
,Add ML Path
, andRemove LoadPath
commands have been removed following deprecation. Users are encouraged to use the existing mechanisms incoq_makefile
ordune
to configure workspaces of Coq theories (#17394, by Emilio Jesus Gallego Arias).Deprecated:
Export
modifier forSet
. Use attributeexport
instead (#17333, by Gaëtan Gilbert).Deprecated: the
nonuniform
attribute, now subsumed bywarnings
with "-uniform-inheritance" (#17716, by Pierre Roux).Deprecated: Using
Qed
withLet
. End the proof withDefined
and useclearbody
instead to get the same behavior (#17544, by Gaëtan Gilbert).Added:
About
now prints information when a constant or inductive is syntactically equal to another through module aliasing (#16796, by Gaëtan Gilbert).Added:
Final Obligation
command (#16817, by Gaëtan Gilbert).Added: The
deprecated
attribute is now supported for definition-like constructions (#16890, fixes #12266, by Maxime Dénès and Gaëtan Gilbert).Added: attributes
warnings
and aliaswarning
to set warnings locally for a command (#16902, fixes #15893, by Gaëtan Gilbert).Added: flag
Printing Unfolded Projection As Match
(off by default) to be able to distinguish unfolded and folded primitive projections (#16994, by Gaëtan Gilbert).Added: option
-time-file
, liketime
but outputting to a file (#17430, by Gaëtan Gilbert).Added:
Validate Proof
runs the type checker on the current proof, complementary withGuarded
which runs the guard checker (#17467, by Gaëtan Gilbert).Added:
clearbody
forLet
to clear the body of a let-in in an interactive proof without kernel enforcement. (This is the behavior that was previously provided by usingQed
, which is now deprecated forLet
s.) (#17544, by Gaëtan Gilbert).Added: option
-time-file
, liketime
but outputting to a file (#17430, by Gaëtan Gilbert).Fixed: universe monomorphic inductives and records do not ignore
Universe Minimization ToSet
(#17285, fixes #13927, by Gaëtan Gilbert).
Command-line tools¶
Changed: Do not pass the
-rectypes
flag by default incoq_makefile
when compiling OCaml code, since it is no longer required by Coq. To re-enable passing the flag, putCAMLFLAGS+=-rectypes
in the local makefile, e.g.,CoqMakefile.local
(see CoqMakefile.local) (#17038, by Karl Palmskog with help from Gaëtan Gilbert).Changed: disable inclusion of variable binders in coqdoc indexes by default, and provide a new coqdoc option
--binder-index
for including them (#17045, fixes #13155, by Karl Palmskog).Added:
coqdoc
handles multiple links to the same source. For example when declaring an inductive typet
all occurences oft
itself and its elimination principles liket_ind
point to its declaration (#17118, by Enrico Tassi).Added: Command line options
-require lib
(replacing-load-vernac-object lib
) and-require-from root lib
respectively equivalent to vernacular commandsRequire lib
andFrom root Require lib
(#17364, by Hugo Herbelin).Added:
coqtimelog2html
command-line tool used to render the timing files produced with-time
(which is passed bycoq_makefile
when environment variableTIMING
is defined) (#17411, by Gaëtan Gilbert).Fixed:
coq_makefile
avoids generating a command containing all files to install in a make rule, which could surpass the maximum single argument size in some developments (#17697, fixes #17721, by Gaëtan Gilbert).
CoqIDE¶
Changed: XML Protocol now sends (and expects) full Coq locations, including line and column information. This makes some IDE operations (such as UTF-8 decoding) more efficient. Clients of the XML protocol can just ignore the new fields if they are not useful for them (#17382, fixes #17023, by Emilio Jesus Gallego Arias).
Standard library¶
Changed: implementation of
Vector.nth
to follow OCaml and compute strict subterms (#16731, fixes #16738, by Andrej Dudenhefner).Changed: drop the unnecessary second assumption
NoDup l'
fromset_diff_nodup
inListSet.v
, with-compat 8.17
providing the old version ofset_diff_nodup
for compatibility (#16926, by Karl Palmskog with help from Traian Florin Şerbănuţă and Andres Erbsen).Changed: Moved instances from
DecidableClass
to files that prove the relevant decidability facts:Bool
,PeanoNat
, andBinInt
(#17021, by Andres Erbsen).Changed:
Hint Extern
btauto.Algebra.bool
locality fromglobal
toexport
(#17281, by Andres Erbsen).Changed:
xorb
to a simpler definition (#17427, by Guillaume Melquiond).Changed lemmas in
Reals/RIneq.v
completeness_weak
renamed asupper_bound_thm
,le_epsilon
renamed asRle_epsilon
,Rplus_eq_R0
renamed asRplus_eq_0
,Req_EM_T
renamed asReq_dec_T
,Rinv_r_simpl_m
renamed asRmult_inv_r_id_m
,Rinv_r_simpl_l
renamed asRmult_inv_r_id_l
,Rinv_r_simpl_r
renamed asRmult_inv_m_id_r
,tech_Rgt_minus
renamed asRgt_minus_pos
,tech_Rplus
renamed asRplus_le_lt_0_neq_0
,IZR_POS_xI
modified with2
instead of1 + 1
,IZR_POS_xO
modified with2
instead of1 + 1
,Rge_refl
modified with>=
instead of<=
(#17036, by Pierre Rousselin, reviewer Laurent Théry).
Removed:
Datatypes.prod_curry
,Datatypes.prod_uncurry
,Datatypes.prodT_curry
,Datatypes.prodT_uncurry
,Combinators.prod_curry_uncurry
,Combinators.prod_uncurry_curry
,Bool.leb
,Bool.leb_implb
,List.skipn_none
,Zdiv.Z_div_mod_eq
,Zdiv.div_Zdiv
,Zdiv.mod_Zmod
,FloatOps.frexp
,FloatOps.ldexp
,FloatLemmas.frexp_spec
,FloatLemmas.ldexp_spec
,RList.Rlist
,Rlist.cons
,Rlist.nil
,RList.Rlength
,Rtrigo_calc.cos3PI4
,Rtrigo_calc.sin3PI4
,MSetRBT.filter_app
after deprecation for at least two Coq versions (#16920, by Olivier Laurent).Deprecated:
List.app_nil_end
,List.app_assoc_reverse
,List.ass_app
,List.app_ass
(#16920, by Olivier Laurent).Deprecated:
Coq.Lists.List.Forall2_refl
(Coq.Lists.List.Forall2_nil
has the same type) (#17646, by Gaëtan Gilbert).Deprecated:
ZArith.Zdigits
in favor ofZ.testbit
. If you are aware of a use case of this module and would be interested in a drop-in replacement, please comment on the PR with information about the context that would benefit from such functinality (#17733, by Andres Erbsen).Deprecated: Deprecation warnings are now generated for
Numbers.Cyclic.Int31.Cyclic31
,NNumbers.Cyclic.Int31.Int31
, andNNumbers.Cyclic.Int31.Ring31
. These modules have been deprecated since Coq 8.10. The modules underNumbers.Cyclic.Int63
remain available (#17734, by Andres Erbsen).Deprecated lemmas in
Reals/RIneq.v
inser_trans_R
,IZR_neq
,double
,double_var
,Rinv_mult_simpl
,Rle_Rinv
,Rlt_Rminus
,Rminus_eq_0
,Rminus_gt_0_lt
,Ropp_div
,Ropp_minus_distr'
,Rplus_sqr_eq_0_l
,sum_inequa_Rle_lt_depr
,S_O_plus_INR_depr
,single_z_r_R1_depr
,tech_single_z_r_R1_depr
,(#17036, by Pierre Rousselin, reviewer Laurent Théry).
Added: lemmas
L_inj
,R_inj
,L_R_neq
,case_L_R
,case_L_R'
toFin.v
, andnil_spec
,nth_append_L
,nth_append_R
,In_nth
,nth_replace_eq
,nth_replace_neq
,replace_append_L
,replace_append_R
,append_const
,map_append
,map2_ext
,append_inj
,In_cons_iff
,Forall_cons_iff
,Forall_map
,Forall_append
,Forall_nth
,Forall2_nth
,Forall2_append
,map_shiftin
,fold_right_shiftin
,In_shiftin
,Forall_shiftin
,rev_nil
,rev_cons
,rev_shiftin
,rev_rev
,map_rev
,fold_left_rev_right
,In_rev
,Forall_rev
toVectorSpec.v
(#16765, closes #6459, by Andrej Dudenhefner).Added: lemmas
iter_swap_gen
,iter_swap
,iter_succ
,iter_succ_r
,iter_add
,iter_ind
,iter_rect
,iter_invariant
forNat.iter
(#17013, by Stefan Haan with help from Jason Gross).Added: module
Zbitwise
with basic relationships between bitwise and arithmetic operations on integers (#17022, by Andres Erbsen).Added: lemmas
forallb_filter
,forallb_filter_id
,partition_as_filter
,filter_length
,filter_length_le
andfilter_length_forallb
(#17027, by Stefan Haan with help from Olivier Laurent and Andres Erbsen).Added: lemmas in
Reals/RIneq.v
:eq_IZR_contrapositive
,INR_0
,INR_1
,INR_archimed
,INR_unbounded
,IPR_2_xH
,IPR_2_xI
,IPR_2_xO
,IPR_eq
,IPR_ge_1
,IPR_gt_0
,IPR_IPR_2
,IPR_le
,IPR_lt
,IPR_not_1
,IPR_xH
,IPR_xI
,IPR_xO
,le_IPR
,lt_1_IPR
,lt_IPR
,minus_IPR
,mult_IPR
,not_1_IPR
,not_IPR
,plus_IPR
,pow_IPR
,Rdiv_0_l
,Rdiv_0_r
,Rdiv_1_l
,Rdiv_1_r
,Rdiv_def
,Rdiv_diag_eq
,Rdiv_diag
,Rdiv_diag_uniq
,Rdiv_eq_compat_l
,Rdiv_eq_compat_r
,Rdiv_eq_reg_l
,Rdiv_eq_reg_r
,Rdiv_mult_distr
,Rdiv_mult_l_l
,Rdiv_mult_l_r
,Rdiv_mult_r_l
,Rdiv_mult_r_r
,Rdiv_neg_neg
,Rdiv_neg_pos
,Rdiv_opp_l
,Rdiv_pos_cases
,Rdiv_pos_neg
,Rdiv_pos_pos
,Rexists_between
,Rge_gt_or_eq_dec
,Rge_gt_or_eq
,Rge_lt_dec
,Rge_lt_dec
,Rgt_le_dec
,Rgt_minus_pos
,Rgt_or_le
,Rgt_or_not_gt
,Rinv_0_lt_contravar
,Rinv_eq_compat
,Rinv_eq_reg
,Rinv_lt_0_contravar
,Rinv_neg
,Rinv_pos
,Rle_gt_dec
,Rle_half_plus
,Rle_lt_or_eq
,Rle_or_gt
,Rle_or_not_le
,Rlt_0_2
,Rlt_0_minus
,Rlt_ge_dec
,Rlt_half_plus
,Rlt_minus_0
,Rlt_or_ge
,Rlt_or_not_lt
,Rminus_def
,Rminus_diag
,Rminus_eq_compat_l
,Rminus_eq_compat_r
,Rminus_plus_distr
,Rminus_plus_l_l
,Rminus_plus_l_r
,Rminus_plus_r_l
,Rminus_plus_r_r
,Rmult_div_assoc
,Rmult_div_l
,Rmult_div_r
,Rmult_div_swap
,Rmult_gt_reg_r
,Rmult_inv_l
,Rmult_inv_m_id_r
,Rmult_inv_r
,Rmult_inv_r_id_l
,Rmult_inv_r_id_m
,Rmult_inv_r_uniq
,Rmult_neg_cases
,Rmult_neg_neg
,Rmult_neg_pos
,Rmult_pos_cases
,Rmult_pos_neg
,Rmult_pos_pos
,Ropp_div_distr_l
,Ropp_eq_reg
,Ropp_neg
,Ropp_pos
,Rplus_0_l_uniq
,Rplus_eq_0
,Rplus_ge_reg_r
,Rplus_gt_reg_r
,Rplus_minus_assoc
,Rplus_minus_l
,Rplus_minus_r
,Rplus_minus_swap
,Rplus_neg_lt
,Rplus_neg_neg
,Rplus_neg_npos
,Rplus_nneg_ge
,Rplus_nneg_nneg
,Rplus_nneg_pos
,Rplus_npos_le
,Rplus_npos_neg
,Rplus_npos_npos
,Rplus_pos_gt
,Rplus_pos_nneg
,Rplus_pos_pos
,Rsqr_def
lemmas in
Reals/R_Ifp.v
:Int_part_spec
,Rplus_Int_part_frac_part
,Int_part_frac_part_spec
(#17036, by Pierre Rousselin, reviewer Laurent Théry).
Added: lemmas
concat_length
,flat_map_length
,flat_map_constant_length
,list_power_length
toLists.List
(#17082, by Stefan Haan with help from Olivier Laurent).
Infrastructure and dependencies¶
Extraction¶
Version 8.17¶
Summary of changes¶
Coq version 8.17 integrates a soundness fix to the Coq kernel along with a few new features and a host of improvements to the Ltac2 language and libraries. We highlight some of the most impactful changes here:
Fixed a logical inconsistency due to
vm_compute
in presence of side-effects in the enviroment (e.g. usingBack
orFail
).It is now possible to dynamically enable or disable notations.
Support multiple scopes in
Arguments
andBind Scope
.The tactics chapter of the manual has many improvements in presentation and wording. The documented grammar is semi-automatically checked for consistency with the implementation.
Fixes to the
auto
andeauto
tactics, to respect hint priorities and the documented use ofsimple apply
. This is a potentially breaking change.New Ltac2 APIs, deep pattern-matching with
as
clauses and handling of literals, support for record types and preterms.Move from
:>
to::
syntax for declaring typeclass fields as instances, fixing a confusion with declaration of coercions.Standard library improvements.
While Coq supports OCaml 5, users are likely to experience slowdowns ranging from +10% to +50% compared to OCaml 4. Moreover, the
native_compute
machinery is not available when Coq is compiled with OCaml 5. Therefore, OCaml 5 support should still be considered experimental and not production-ready.
See the Changes in 8.17.0 section below for the detailed list of changes, including potentially breaking changes marked with Changed. Coq's reference manual for 8.17, documentation of the 8.17 standard library and developer documentation of the 8.17 ML API are also available.
Ali Caglayan, Emilio Jesús Gallego Arias, Gaëtan Gilbert and Théo Zimmermann worked on maintaining and improving the continuous integration system and package building infrastructure.
Erik Martin-Dorel has maintained the Coq Docker images that are used in many Coq projects for continuous integration.
Maxime Dénès, Paolo G. Giarrusso, Huỳnh Trần Khanh, and Laurent Théry have maintained the VsCoq extension for VS Code.
The opam repository for Coq packages has been maintained by Guillaume Claret, Karl Palmskog, Matthieu Sozeau and Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
The Coq Platform has been maintained by Michael Soegtrop, with help from Karl Palmskog, Pierre Roux, Enrico Tassi and Théo Zimmermann.
Our current maintainers are Yves Bertot, Frédéric Besson, Ana Borges, Ali Caglayan, Tej Chajed, Cyril Cohen, Pierre Corbineau, Pierre Courtieu, Maxime Dénès, Andres Erbsen, Jim Fehrle, Julien Forest, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Georges Gonthier, Benjamin Grégoire, Jason Gross, Hugo Herbelin, Vincent Laporte, Olivier Laurent, Assia Mahboubi, Kenji Maillard, Guillaume Melquiond, Pierre-Marie Pédrot, Clément Pit-Claudel, Pierre Roux, Kazuhiko Sakaguchi, Vincent Semeria, Michael Soegtrop, Arnaud Spiwack, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Anton Trunov, Li-yao Xia and Théo Zimmermann. See the Coq Team face book page for more details.
The 45 contributors to the 8.17 version are: Reynald Affeldt, Tanaka Akira, Lasse Blaauwbroek, Stephan Boyer, Ali Caglayan, Cyril Cohen, Maxime Dénès, Andrej Dudenhefner, Andres Erbsen, František Farka, Jim Fehrle, Paolo G. Giarrusso, Gaëtan Gilbert, Jason Gross, Alban Gruin, Stefan Haan, Hugo Herbelin, Wolf Honore, Bodo Igler, Jerry James, Emilio Jesús Gallego Arias, Ralf Jung, Jan-Oliver Kaiser, Wojciech Karpiel, Chantal Keller, Thomas Klausner, Olivier Laurent, Yishuai Li, Guillaume Melquiond, Karl Palmskog, Sudha Parimala, Pierre-Marie Pédrot, Valentin Robert, Pierre Roux, Julin S, Dmitry Shachnev, Michael Soegtrop, Matthieu Sozeau, Naveen Srinivasan, Sergei Stepanenko, Karolina Surma, Enrico Tassi, Li-yao Xia and Théo Zimmermann.
The Coq community at large helped improve this new version via the GitHub issue and pull request system, the coq-club@inria.fr mailing list, the Discourse forum and the Coq Zulip chat.
Version 8.17's development spanned 5 months from the release of Coq 8.16.0. Théo Zimmermann is the release manager of Coq 8.17. This release is the result of 414 merged PRs, closing 105 issues.
Changes in 8.17.0¶
Kernel¶
Fixed: inconsistency linked to
vm_compute
. The fix removes a vulnerable cache, thus it may result in slowdowns whenvm_compute
is used repeatedly, if you encounter such slowdowns please report your use case (#16958, fixes #16957, by Gaëtan Gilbert).Fixed: Unexpected anomaly when checking termination of fixpoints containing
match
expressions with inaccessible branches (#17116, fixes #17073, by Hugo Herbelin).
Specification language, type inference¶
Changed:
Unused variable
warning triggers even when catching a single case. This warning used to be triggered only when the unused variable was catching at least two cases (#16135, by Pierre Roux).Fixed: Pattern-matching clauses were possibly lost when matching over a constructor from a singleton inductive type in the presence of implicit coercions (#17138, fixes #17137, by Hugo Herbelin).
Fixed: Possible anomaly when using syntax
term.(proj)
with projections defined in sections (#17174, fixes #17173, by Hugo Herbelin).
Notations¶
Changed: When multiple tokens match the beginning of a sequence of characters, the longest matching token not cutting a subsequence of contiguous letters in the middle is used. Previously, this was only the longest matching token. See lexical conventions for details and examples (#16322, fixes #4712, by Hugo Herbelin).
Added:
Enable Notation
andDisable Notation
commands to enable or disable previously defined notations (#12324 and #16945, by Hugo Herbelin and Pierre Roux, extending previous work by Lionel Rieg, review by Jim Fehrle).Added: Support for multiple scopes in the
Arguments
command (#16472, by Pierre Roux, review by Jim Fehrle, Hugo Herbelin and Enrico Tassi).Added: Attributes
add_top
andadd_bottom
to bind multiple scopes through theBind Scope
command (#16472, by Pierre Roux, review by Jim Fehrle, Hugo Herbelin and Enrico Tassi).
Tactics¶
Changed: Documentation in the tactics chapter to give the current correct syntax, consolidate tactic variants for each tactic into a single, unified description for each tactic and many wording improvements. With this change, following similar changes to other chapters in previous releases, the correctness of documented syntax is assured by semi-automated tooling in all chapters except SSReflect (#15015, #16498, and #16659, by Jim Fehrle, reviewed by Théo Zimmermann, with help from many others).
Changed:
eauto
respects priorities ofExtern
hints (#16289, fixes #5163 and #16282, by Andrej Dudenhefner).Changed: less discrepancies between
auto
hint evaluation andsimple apply
,exact
tactics (#16293, fixes #16062 and #16323, by Andrej Dudenhefner).Removed:
absurd_hyp
tactic, that was marked as obsolete 15 years ago. Usecontradict
instead (#16670, by Théo Zimmermann).Removed: the undocumented
progress_evars
tactical (#16843, by Théo Zimmermann).Deprecated: the default
intuition_solver
(seeintuition
) now outputs warningintuition-auto-with-star
if it solves a goal withauto with *
that was not solved with justauto
. In a future version it will be changed to justauto
. Useintuition tac
locally orLtac Tauto.intuition_solver ::= tac
globally to silence the warning in a forward-compatible way with your choice of tactictac
(auto
,auto with *
,auto with
your prefered databases, or any other tactic) (#16026, by Gaëtan Gilbert).Deprecated:
>
clear modifier that could be used in some tactics likeapply
andrewrite
but was never documented. Open an issue if you actually depend on this feature (#16407, by Théo Zimmermann).Fixed:
auto
now properly updates local hypotheses after hint application (#16302, fixes #15814 and #6332, by Andrej Dudenhefner).Fixed: Make the behavior of
destruct ... using ...
more powerful and more similar todestruct ...
(#16605, by Lasse Blaauwbroek).Fixed: typeclass inference sometimes caused remaining holes to fail to be detected (#16743, fixes #5239, by Gaëtan Gilbert).
Ltac language¶
Changed:
Ltac
redefinitions (with::=
) now respectlocal
(#16106, by Gaëtan Gilbert).Changed: In
match goal
,match goal with hyp := body : typ |- _
is syntax sugar formatch goal with hyp := [ body ] : typ |- _
i.e. it matchestyp
with the type of the hypothesis rather than matching the body as a cast term. This transformation used to be done with any kind of cast (e.g. VM cast<:
) and is now done only for default casts:
(#16764, by Gaëtan Gilbert).
Ltac2 language¶
Changed:
Ltac2.Bool
notations are now in a moduleLtac2.Bool.BoolNotations
(exported by default), so that these notations can be imported separately (#16536, by Jason Gross).Changed:
Constr.in_context
enforces that theconstr
passed to it is a type (#16547, fixes #16540, by Gaëtan Gilbert).Changed: goal matching functions from
Ltac2.Pattern
(matches_goal
,lazy_goal_match0
,multi_goal_match0
andone_goal_match0
) have changed types to support matching hypothesis bodies (#16655, by Gaëtan Gilbert).Added: Deep pattern matching for Ltac2 (#16023, by Gaëtan Gilbert).
Added: patterns for Ltac2 matches:
as
, records and literal integers and strings (#16179, by Gaëtan Gilbert).Added: APIs for working with strings:
Message.to_string
,String.concat
,cat
,equal
,compare
,is_empty
(#16217, by Gaëtan Gilbert).Added:
Ltac2.Constr.Unsafe.liftn
(#16413, by Jason Gross).Added:
Ltac2.Constr.Unsafe.closedn
,Ltac2.Constr.Unsafe.is_closed
,Ltac2.Constr.Unsafe.occur_between
,Ltac2.Constr.Unsafe.occurn
(#16414, by Jason Gross).Added:
Ltac2.List.equal
(#16429, by Jason Gross).Added:
Print Ltac2
,Print Ltac2 Signatures
andLocate
can now find Ltac2 definitions (#16466, fixes #16418 and #16415, by Gaëtan Gilbert).Added:
Ltac2.Array.for_all2
andLtac2.Array.equal
(#16535, by Jason Gross).Added:
Ltac2.Constant.equal
,Ltac2.Constant.t
,Ltac2.Constructor.equal
,Ltac2.Constructor.t
,Ltac2.Evar.equal
,Ltac2.Evar.t
,Ltac2.Float.equal
,Ltac2.Float.t
,Ltac2.Meta.equal
,Ltac2.Meta.t
,Ltac2.Proj.equal
,Ltac2.Proj.t
,Ltac2.Uint63.equal
,Ltac2.Uint63.t
,Ltac2.Char.equal
,Ltac2.Char.compare
,Ltac2.Constr.Unsafe.Case.equal
(#16537, by Jason Gross).Added:
Ltac2.Option.equal
(#16538, by Jason Gross).Added: syntax for Ltac2 record update
{ foo with field := bar }
(#16552, fixes #10117, by Gaëtan Gilbert).Added: Ltac2 record expressions support punning, i.e.
{ foo; M.bar }
is equivalent to{ foo := foo; M.bar := bar }
(#16556, by Gaëtan Gilbert).Added:
match! goal
support for matching hypothesis bodies (#16655, fixes #12803, by Gaëtan Gilbert).Added: quotation and syntax class for preterms (#16740, by Gaëtan Gilbert).
SSReflect¶
Added: port the additions made to
ssrfun.v
andssrbool.v
in math-comp PR #872 and PR #874, namely definitionsolift
andpred_oapp
as well as lemmasall_sig2_cond
,compA
,obindEapp
,omapEbind
,omapEapp
,omap_comp
,oapp_comp
,olift_comp
,ocan_comp
,eqbLR
,eqbRL
,can_in_pcan
,pcan_in_inj
,in_inj_comp
,can_in_comp
,pcan_in_comp
andocan_in_comp
(#16158, by Pierre Roux).
Commands and options¶
Changed: commands which set tactic options (currently
Firstorder Solver
andObligation Tactic
, as well as any defined by third party plugins) now supportexport
locality. Note that such commands usingglobal
withoutexport
or using no explicit locality outside sections apply their effects when any module containing it (recursively) is imported. This will change in a future version. (#15274, fixes #15072, by Gaëtan Gilbert).Changed:
Hint
andInstance
commands with no locality attribute are deprecated. Previous versions generated a warning, but this version generates an error by default. This includes allHint
commands described in Creating Hints,Hint Rewrite
, andInstance
. As mentioned in the error, please add an explicit locality to the hint command. The default was #[global
], but we recommend using #[export
] where possible (#16004, fixes #13394, by Ali Caglayan).Changed: Transparent obligations generated by
Program
do not produce an implicitHint Unfold
anymore (#16340, by Pierre-Marie Pédrot).Changed:
Print Typeclasses
replaces the undocumentedPrint TypeClasses
command which displays the list of typeclasses (#16690, fixes #16686, by Ali Caglayan).Changed: The -async-proofs-tac-j command line option now accepts the argument 0, which makes
par
block interpreted without spawning any new process (#16837, by Pierre-Marie Pédrot).Removed: the
Program Naming
flag, which was introduced as an immediately deprecated option in Coq 8.16 (#16519, by Pierre-Marie Pédrot).Removed: undocumented and broken
Solve Obligation
command (theSolve Obligations
command is untouched) (#16842, by Théo Zimmermann).Deprecated
:>
syntax, to declare fields of Typeclasses as instances, since it is now replaced by::
(seeof_type_inst
). This will allow, in a future release, making:>
declare Implicit Coercions as it does in record definitions (#16230, fixes #16224, by Pierre Roux, reviewed by Ali Caglayan, Jim Fehrle, Gaëtan Gilbert and Pierre-Marie Pédrot).Added: An improved description of
Proof using
and section variables (#16168, by Jim Fehrle).Added:
::
syntax (seeof_type_inst
) to declare fields of records as typeclass instances (#16230, fixes #16224, by Pierre Roux, reviewed by Ali Caglayan, Jim Fehrle, Gaëtan Gilbert and Pierre-Marie Pédrot).Added: The
Print Keywords
command, which prints all the currently-defined parser keywords and tokens (#16438, fixes #16375, by Gaëtan Gilbert).Added:
Print Grammar
can print arbitrary nonterminals or the whole grammar instead of a small adhoc list of nonterminals (#16440, by Gaëtan Gilbert).Fixed:
Fast Name Printing
flag no longer causes variable name capture when displaying a goal (#16395, fixes #14141, by Wojciech Karpiel).Fixed:
vm_compute
ignored thebytecode-compiler
command line flag (#16931, fixes #16929, by Gaëtan Gilbert).Fixed: The
Proof Mode
command now gives an error if the specified proof mode doesn't exist. The command was not previously documented (#16981, fixes #16602, by Jim Fehrle).Fixed: Backtracking over grammar modifications from plugins (such as added commands) (#17069, fixes #12575, by Gaëtan Gilbert).
Fixed: Anomaly instead of regular error on unsupported applied
fix
inFunction
(#17113, fixes #17110, by Hugo Herbelin).
Command-line tools¶
Added: New documentation section Coq configuration basics covering use cases such as setting up Coq with opam, where/how to set up source code for your projects and use of _CoqProject (#15888, by Jim Fehrle).
Added: In _CoqProject files, expand paths that are directories to include appropriate files in (sub)directories (#16308, by Jim Fehrle).
Fixed: issues when using
coq_makefile
to build targets requiring both.vo
and.glob
files (typically documentation targets), wheremake
would run multiplecoqc
processes on the same source file with racy behaviour (only fixed when using amake
supporting "grouped targets" such as GNU Make 4.3) (#16757, by Gaëtan Gilbert).Fixed: Properly process legacy attributes such as
Global
andPolymorphic
in coqdoc to avoid omissions when using the-g
(Gallina only) option (#17090, fixes #15933, by Karl Palmskog).
Standard library¶
Changed: Class
Saturate
inZifyCLasses.v
,PRes
now also takes operands (#16355, by František Farka on behalf of BedRock Systems, Inc.).Changed: For uniformity of naming and ease of remembering,
R_dist
and theorems mentioningR_dist
in their name become available with spellingRdist
(#16874, by Hugo Herbelin).Removed: from
Nat
andN
superfluous lemmasrs_rs'
,rs'_rs''
,rbase
,A'A_right
,ls_ls'
,ls'_ls''
,rs'_rs''
,lbase
,A'A_left
, and also redundant non-negativity assumptions ingcd_unique
,gcd_unique_alt
,divide_gcd_iff
, andgcd_mul_diag_l
(#16203, by Andrej Dudenhefner).Deprecated: notation
_ ~= _
forJMeq
inCoq.Program.Equality
(#16436, by Gaëtan Gilbert).Deprecated: lemma
Finite_alt
inFinFun.v
, which is a weaker version of the newly added lemmaFinite_dec
(#16489, fixes #16479, by Bodo Igler, with help from Olivier Laurent).Deprecated:
Zmod
,Zdiv_eucl_POS
,Zmod_POS_bound
,Zmod_pos_bound
, andZmod_neg_bound
inZArith.Zdiv
(#16892, by Andres Erbsen).Deprecated:
Cyclic.ZModulo.ZModulo
because there have been no known use cases for this module and because it does not implementZ/nZ
for arbitraryn
as one might expect based on the name. The same construction will remain a part of the Coq test suite to ensure consistency ofCyclicAxioms
(#16914, by Andres Erbsen).Added: lemmas
Permutation_incl_cons_inv_r
,Permutation_pigeonhole
,Permutation_pigeonhole_rel
toPermutation.v
, andForall2_cons_iff
,Forall2_length
,Forall2_impl
,Forall2_flip
,Forall_Exists_exists_Forall2
toList.v
(#15986, by Andrej Dudenhefner, with help from Dominique Larchey-Wendling and Olivier Laurent).Added: modules
Nat.Div0
andNat.Lcm0
inPeanoNat
, andN.Div0
andN.Lcm0
inBinNat
containing lemmas regardingdiv
andmod
, which take into accountn div 0 = 0
andn mod 0 = n
. Strictly weaker lemmas are deprecated, and will be removed in the future. After the weaker lemmas are removed, the modulesDiv0
andLcm0
will be deprecated, and their contents included directly intoNat
andN
. Locally, you can useModule Nat := Nat.Div0.
orModule Nat := Nat.Lcm0.
to approximate this inclusion (#16203, fixes #16186, by Andrej Dudenhefner).Added: lemma
measure_induction
inNat
andN
analogous toWf_nat.induction_ltof1
, which is compatible with theusing
clause for theinduction
tactic (#16203, by Andrej Dudenhefner).Added: three lemmata related to finiteness and decidability of equality:
Listing_decidable_eq
,Finite_dec
toFinFun.v
and lemmaNoDup_list_decidable
toListDec.v
(#16489, fixes #16479, by Bodo Igler, with help from Olivier Laurent and Andrej Dudenhefner).Added: lemma
not_NoDup
toListDec.v
andNoDup_app_remove_l
,NoDup_app_remove_r
toList.v
(#16588, by Stefan Haan with a lot of help from Olivier Laurent and Ali Caglayan).Added: the
skipn_skipn
lemma inLists/List.v
(#16632, by Stephan Boyer).Added: lemmas
nth_error_ext
,map_repeat
,rev_repeat
toList.v
, andto_list_nil_iff
,to_list_inj
toVectorSpec.v
(#16756, by Stefan Haan).Added: transparent
extgcd
to replace opaqueeuclid
,euclid_rec
,Euclid
, andEuclid_intro
inZnumtheory
. Deprecated compatibility wrappers are provided (#16915, by Andres Erbsen).
Infrastructure and dependencies¶
Changed: Coq is now built entirely using the Dune build system. Packagers and users that build Coq manually must use the new build instructions in the documentation (#15560, by Ali Caglayan, Emilio Jesus Gallego Arias, and Rudi Grinberg).
Changed: Coq is not compiled with OCaml's
-rectypes
option anymore. This means plugins which do not exploit it can also stop passing it to OCaml (#16007, by Gaëtan Gilbert).Changed: Building Coq now requires Dune >= 2.9 (#16118, by Emilio Jesus Gallego Arias).
Changed: Coq Makefile targets
pretty-timed
,make-pretty-timed
,make-pretty-timed-before
,make-pretty-timed-after
,print-pretty-timed
,print-pretty-timed-diff
,print-pretty-single-time-diff
now generate more readable timing tables when absolute paths are used in_CoqProject
/ the arguments tocoq_makefile
, by stripping off the absolute prefix (#16268, by Jason Gross).Changed: Coq's configure script now defaults to
-native-compiler no
. Previously, the default was-native-compiler ondemand
, except on Windows. The behavior for users installing through opam does not change, i.e., it is-native-compiler no
if thecoq-native
package is not installed, and-native-compiler yes
otherwise (#16997, by Théo Zimmermann).Removed: the
-coqide
switch toconfigure
in Coq's build infrastructure (it stopped controlling what got compiled in the move to dune) (#16512, by Gaëtan Gilbert).Removed: the
-nomacintegration
configure flag for CoqIDE. Now CoqIDE will always build with the proper platform-specific integration if available (#16531, by Emilio Jesus Gallego Arias).Added: Coq now supports OCaml 5; note that OCaml 5 is not compatible with Coq's native reduction machine (#15494, #16925, #16947, #16959, #16988, #16991, #16996, #16997, #16999, #17010, and #17015 by Emilio Jesus Gallego Arias, Gaëtan Gilbert, Guillaume Melquiond, Pierre-Marie Pédrot, and others).
Added: OCaml 4.14 is now officially supported (#15867, by Gaëtan Gilbert).
Miscellaneous¶
Changed: Module names are now added to the loadpath in alphabetical order for each (sub-)directory. Previously they were added in the order of the directory entries (as shown by "ls -U") (#16725, by Jim Fehrle).
Changes in 8.17.1¶
A variety of bug fixes and improvements to error messages, including:
Fixed: in some cases, coqdep emitted incorrect paths for META files which prevented dune builds for plugins from working correctly (#17270, fixes #16571, by Rodolphe Lepigre).
Fixed: Shadowing of record fields in extraction to OCaml (#17324, fixes #12813 and #14843 and #16677, by Hugo Herbelin).
Fixed: an impossible to turn off debug message "backtracking and redoing byextend on ..." (#17495, fixes #17488, by Gaëtan Gilbert).
Fixed: major memory regression affecting MathComp 2 (#17743, by Enrico Tassi and Pierre Roux).
Version 8.16¶
Summary of changes¶
Coq version 8.16 integrates changes to the Coq kernel and performance improvements along with a few new features. We highlight some of the most impactful changes here:
The guard checker (see
Guarded
) now ensures strong normalization under any reduction strategy.Irrelevant terms (in the
SProp
sort) are now squashed to a dummy value during conversion, fixing a subject reduction issue and making proof conversion faster.Introduction of reversible coercions, which allow coercions relying on meta-level resolution such as type-classes or canonical structures. Also allow coercions that do not fullfill the uniform inheritance condition.
Generalized rewriting support for rewriting with
Type
-valued relations and inType
contexts, using theClasses.CMorphisms
library.Added the boolean equality scheme command for decidable inductive types.
Added a Print Notation command.
Incompatibilities in name generation for Program obligations,
eauto
treatment of tactic failure levels, use ofident
in notations, parsing of module expressions.Standard library reorganization and deprecations.
Improve the treatment of standard library numbers by
Extraction
.
See the Changes in 8.16.0 section below for the detailed list of changes, including potentially breaking changes marked with Changed. Coq's reference manual for 8.16, documentation of the 8.16 standard library and developer documentation of the 8.16 ML API are also available.
Ali Caglayan, Emilio Jesús Gallego Arias, Gaëtan Gilbert and Théo Zimmermann worked on maintaining and improving the continuous integration system and package building infrastructure.
Erik Martin-Dorel has maintained the Coq Docker images that are used in many Coq projects for continuous integration.
The opam repository for Coq packages has been maintained by Guillaume Claret, Karl Palmskog, Matthieu Sozeau and Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
The Coq Platform has been maintained by Michael Soegtrop, with help from Karl Palmskog, Enrico Tassi and Théo Zimmermann.
Our current maintainers are Yves Bertot, Frédéric Besson, Ana Borges, Ali Caglayan, Tej Chajed, Cyril Cohen, Pierre Corbineau, Pierre Courtieu, Maxime Dénès, Jim Fehrle, Julien Forest, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Georges Gonthier, Benjamin Grégoire, Jason Gross, Hugo Herbelin, Vincent Laporte, Olivier Laurent, Assia Mahboubi, Kenji Maillard, Guillaume Melquiond, Pierre-Marie Pédrot, Clément Pit-Claudel, Pierre Roux, Kazuhiko Sakaguchi, Vincent Semeria, Michael Soegtrop, Arnaud Spiwack, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Anton Trunov, Li-yao Xia and Théo Zimmermann. See the Coq Team face book page for more details.
The 57 contributors to the 8.16 versions are Tanaka Akira, Frédéric Besson, Martin Bodin, Ana Borges, Ali Caglayan, Minki Cho, Cyril Cohen, Juan Conejero, "stop-cran", Adrian Dapprich, Maxime Dénès, Stéphane Desarzens, Christian Doczkal, Andrej Dudenhefner, Andres Erbsen, Jim Fehrle, Emilio Jesús Gallego Arias, Attila Gáspár, Paolo G. Giarrusso, Gaëtan Gilbert, Rudi Grinberg, Jason Gross, Hugo Herbelin, Wolf Honore, Jasper Hugunin, Bart Jacobs, Pierre Jouvelot, Ralf Jung, Grant Jurgensen, Jan-Oliver Kaiser, Wojciech Karpiel, Thomas Klausner, Ethan Kuefner, Fabian Kunze, Olivier Laurent, Yishuai Li, Erik Martin-Dorel, Guillaume Melquiond, Jean-Francois Monin, Pierre-Marie Pédrot, Rudy Peterson, Clément Pit-Claudel, Seth Poulsen, Ramkumar Ramachandra, Pierre Roux, Takafumi Saikawa, Kazuhiko Sakaguchi, Gabriel Scherer, Vincent Semeria, Kartik Singhal, Michael Soegtrop, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Anton Trunov, Li-yao Xia and Théo Zimmermann.
The Coq community at large helped improve this new version via the GitHub issue and pull request system, the coq-club@inria.fr mailing list, the Discourse forum and the Coq Zulip chat.
Version 8.16's development spanned 6 months from the release of Coq 8.15.0. Pierre-Marie Pédrot is the release manager of Coq 8.16. This release is the result of 356 merged PRs, closing 99 issues.
Changes in 8.16.0¶
Kernel¶
Changed: Fixpoints are now expected to be guarded even in subterms erasable by reduction, thus getting rid of an artificial obstacle preventing to lift the assumption of weak normalization of Coq to an assumption of strong normalization; for instance (barring implementation bugs) termination of the type-checking algorithm of Coq is now restored (of course, as usual, up to the assumption of the consistency of set theory and type theory, i.e., equivalently, up to the weak normalization of type theory, a "physical" assumption, which has not been contradicted for decades and which specialists commonly believe to be a truth) (#15434, incidentally fixes the complexity issue #5702, by Hugo Herbelin).
Changed: Flag
Unset Guard Checking
nevertheless requires fixpoints to have an argument marked as decreasing in a type which is inductive (#15668, fixes #15621, by Hugo Herbelin).Removed: Template polymorphism is now forbidden for mutual inductive types (#15965, by Gaëtan Gilbert).
Fixed: Inlining of non-logical objects (notations, hints, ...) was missing when applying a functor returning one of its arguments as e.g. in
Module F (E:T) := E
(#15412, fixes #15403, by Hugo Herbelin).Fixed: We introduce a new irrelevant term in the reduction machine. It is used to shortcut computation of terms living in a strict proposition, and behaves as an exception. This restores subject reduction, and also makes conversion of large terms in SProp cheap (#15575, fixes #14015, by Pierre-Marie Pédrot).
Fixed: performance blowups while inferring variance information for Cumulative, NonCumulative inductive types (#15662, fixes #11741, by Gaëtan Gilbert).
Specification language, type inference¶
Added: New clause
as ident
to theRecord
command to specify the name of the main argument to use by default in the type of projections (#14563, by Hugo Herbelin).Added: Reversible coercions are coercions which cannot be represented by a regular coercion (a Gallina function) but rather a meta procedure, such as type class inference or canonical structure resolution (#15693, by Cyril Cohen, Pierre Roux, Enrico Tassi, reviewed by Ali Caglayan, Jim Fehrle and Gaëtan Gilbert).
Added: support for coercions not fulfilling the uniform inheritance condition, allowing more freedom for the parameters that are now inferred using unification, canonical structures or typeclasses (#15789, fixes #2828, #4593, #3115, #5222, #9696 and #8540, by Pierre Roux, reviewed by Ali Caglayan, Enrico Tassi, Kazuhiko Sakaguchi and Jim Fehrle).
Fixed: interpretation of
{struct}
fixpoint annotations when the principal argument comes from an implicit generalization (#15581, fixes #13157, by Gaëtan Gilbert).
Notations¶
Removed:
_
inident
entries in notations, which was deprecated in favor ofname
in 8.13. When you see messages likeError: Notation "[ rel _ _ : _ | _ ]" is already defined at level 0 with arguments name, name, constr, constr while it is now required to be at level 0 with arguments ident, ident, constr, constr.
replace
ident
withname
in theNotation
command. To ease the change, you can fix thedeprecated-ident-entry
warnings in Coq 8.15 (or 8.14 or 8.13). The warning can be turned into an error with-arg -w -arg +deprecated-ident-entry
in the_CoqProject
file (#15754, by Pierre Roux).Added: When defining a recursive notation referring to another recursive notation, expressions of the form
x .. y
can be used where a sequence of binders is expected (#15291, grants #7911, by Hugo Herbelin).Fixed: Coercions are disabled when typechecking parsers and printers of
Number Notation
(#15884, fixes #15843, by Pierre Roux).
Tactics¶
Changed: The
RewriteRelation
type class is now used to declare relations inferable by thesetoid_rewrite
tactic to constructProper
instances. This can break developments that relied on existingReflexive
instances to infer relations. The fix is to simply add a (backwards compatible)RewriteRelation
declaration for the relation. This change allows to set stricter modes on the relation type classesReflexive
,Symmetric
, etc. (#13969, fixes #7916, by Matthieu Sozeau).Changed: The
setoid_rewrite
tactic can now properly recognize homogeneous relations applied to types in different universes (#14138, fixes #13618, by Matthieu Sozeau).Changed: The
eauto
tactic does not propagate internal Ltac failures with level > 0 anymore. Any failure caused by a hint now behaves as if it were a level 0 error (#15215, fixes #15214, by Pierre-Marie Pédrot).Changed:
rewrite
when used to rewrite in multiple hypotheses (egrewrite foo in H,H'
) requires that the term (foo
) does not depend on the hypotheses it rewrites. When usingrewrite in *
, this means we only rewrite in hypotheses which do not appear in the term (#15426, fixes #3051 and #15448, by Gaëtan Gilbert).Changed: When it fails,
assert_succeeds
fails with the argument tactic's original error instead ofTactic failure: <tactic closure> fails.
(#15728, fixes #10970, by Gaëtan Gilbert).Deprecated: the
instantiate
tactic without arguments. Since the move to the monadic tactic engine in 8.5, it was behaving as the identity (#15277, by Pierre-Marie Pédrot).Added: generalized rewriting now supports rewriting with (possibly polymorphic) relations valued in
Type
. UseClasses.CMorphisms
instead ofClasses.Morphisms
to declareProper
instances forrewrite
(orsetoid_rewrite
) to use when rewriting withType
valued relations (#14137, fixes #4632, #5384, #5521, #6278, #7675, #8739, #11011, #12240, and #15279, by Matthieu Sozeau helped by Ali Caglayan).Added: Tactics to obtain a micromega cone expression (aka witness) from an already reified goal. Using those tactics, the user can develop their own micromega tactics for their own types, using their own parsers (#15921, by Pierre Roux, reviewed by Frédéric Besson and Jim Fehrle).
Fixed:
typeclasses eauto
used with multiple hint databases respects priority differences for hints from separate databases (#15289, fixes #5304, by Gaëtan Gilbert).Fixed:
cbn
has better support for combiningsimpl nomatch
,!
and/
specifiers (c.f.Arguments
) (#15657, fixes #3989 and #15206, by Gaëtan Gilbert).
Tactic language¶
Changed: Ltac
match
does not fail when the term to match contains an unfolded primitive projection (#15559, fixes #15554, by Gaëtan Gilbert).Added:
Ltac2
understandstoplevel_selector
and obeysDefault Goal Selector
. Note thatpar:
is buggy when combined withabstract
. UnlikeLtac1
evenpar: abstract tac
is not properly treated (#15378, by Gaëtan Gilbert).Added: Ltac2
Int
functionsdiv
,mod
,asr
,lsl
,lsr
,land
,lor
,lxor
andlnot
(#15637, by Michael Soegtrop).Fixed: Ltac2
apply
andeapply
not unifying with implicit arguments; unification inconsistent withexact
andeexact
(#15741, by Ramkumar Ramachandra).
SSReflect¶
Commands and options¶
Changed:
Module
now only allows parentheses around module arguments. For instance,Module M := (F X).
is now a parsing error (#15355, by Gaëtan Gilbert).Changed:
Fail
no longer catches anomalies, which it has done since Coq version 8.11. Now it only catches user errors (#15366, by Hugo Herbelin).Changed: Program Definition in universe monomorphic mode does not accept non-extensible universe declarations (#15424, fixes #15410, by Gaëtan Gilbert).
Changed: The algorithm for name generation of anonymous variables for
Program
subproofs is now the same as the one used in the general case. This can create incompatibilities in scripts relying on such autogenerated names. The old scheme can be reactivated using the deprecated flagProgram Naming
(#15442, by Pierre-Marie Pédrot).Removed:
Universal Lemma Under Conjunction
flag, that was deprecated in 8.15 (#15268, by Théo Zimmermann).Removed:
Abort
no longer takes anident
as an argument (it has been ignored since 8.5) (#15669, by Gaëtan Gilbert).Removed:
Simplex
flag, that was deprecated in 8.14.lia
andlra
will always use the simplex solver (that was already the default behaviour) (#15690, by Frédéric Besson).Deprecated:
Add LoadPath
andAdd Rec LoadPath
. If this command is an important feature for you, please open an issue onGitHub <https://github.com/coq/coq/issues>
and explain your workflow (#15652, by Gaëtan Gilbert).Deprecated: the
Typeclasses Filtered Unification
flag. Due to a buggy implementation, it is unlikely this is used in the wild (#15752, by Pierre-Marie Pédrot).Added:
Scheme Boolean Equality
command to generate the boolean equality for an inductive type whose equality is decidable. It is useful when Coq is able to generate the boolean equality but isn't powerful enough to prove the decidability of equality (unlikeScheme Equality
, which tries to prove the decidability of the type) (#15526, by Hugo Herbelin).Added: New more extensive algorithm based on the "parametricity" translation for canonically generating Boolean equalities associated to a decidable inductive type (#15527, by Hugo Herbelin).
Added:
From … Dependency
command to declare a dependency of a.v
file on an external file. Thecoqdep
tool generates build dependencies accordingly (#15650, fixes #15600, by Enrico Tassi).Added:
Print Notation
command that prints the level and associativity of a given notation definition string (#15683, fixes #14907 and #4436 and #7730, by Ali Caglayan and Ana Borges, with help from Emilio Jesus Gallego Arias).Added: a warning when trying to deprecate a definition (#15760, by Pierre Roux).
Added: A deprecation warning that the
Class >
syntax, which currently does nothing, will in the future declare coercions as it does when used inRecord
commands (#15802, by Pierre Roux, reviewed by Gaëtan Gilbert, Ali Caglayan, Jason Gross, Jim Fehrle and Théo Zimmermann).Added: the
nonuniform
boolean attribute that silences the non-uniform-inheritance warning when user needs to declare such a coercion on purpose (#15853, by Pierre Roux, reviewed by Gaëtan Gilbert and Jim Fehrle).Added: All commands which can import modules (e.g.
Module Import M.
,Module F (Import X : T).
,Require Import M.
, etc) now supportimport_categories
.Require Import
andRequire Export
also supportfiltered_import
(#15945, fixes #14872, by Gaëtan Gilbert).Fixed: Make
Require Import M.
equivalent toRequire M. Import M.
(#15347, fixes #3556, by Maxime Dénès).
Command-line tools¶
Added: coq_makefile variable
COQPLUGININSTALL
to configure the installation of ML plugins (#15788, by Cyril Cohen and Enrico Tassi).Added: Added
-bytecode-compiler yesno
flag forcoqchk
enablingvm_compute
during checks, which is off by default (#15886, by Ali Caglayan).Fixed:
coqdoc
confused by the presence of commandLoad
in a file (#15511, fixes #15497, by Hugo Herbelin).
CoqIDE¶
Added: Documentation of editing failed async mode proofs, how to configure key bindings and various previously undocumented details (#16070, by Jim Fehrle).
Standard library¶
Changed: the
signature
scope ofClasses.CMorphisms
intosignatureT
(#15446, by Olivier Laurent).Changed: the locality of typeclass instances
Permutation_app'
andPermutation_cons
fromglobal
toexport
(#15597, fixes #15596, by Gaëtan Gilbert).Removed:
Int63
, which was deprecated in favor ofUint63
in 8.14 (#15754, by Pierre Roux).Deprecated: some obsolete files from the
Arith
part of the standard library (Div2
,Even
,Gt
,Le
,Lt
,Max
,Min
,Minus
,Mult
,NPeano
,Plus
). ImportArith_base
instead of these files. References to items in the deprecated files should be replaced with references toPeanoNat.Nat
as suggested by the warning messages. Concerning the definitions of parity properties (even and odd), it is recommended to useNat.Even
andNat.Odd
. If an inductive definition of parity is required, the mutually inductiveNat.Even_alt
andNat.Odd_alt
can be used. However, induction principles forNat.Odd
andNat.Even
are available asNat.Even_Odd_ind
andNat.Odd_Even_ind
. The equivalence between the non-inductive and mutually inductive definitions of parity can be found inNat.Even_alt_Even
andNat.Odd_alt_Odd
. AllHint
declarations in thearith
database have been moved toArith_prebase
andArith_base
. To use the results about Peano arithmetic, we recommend importingPeanoNat
(orArith_base
to base it on thearith
hint database) and using theNat
module.Arith_prebase
has been introduced temporarily to ensure compatibility, but it will be removed at the end of the deprecation phase, e.g. in 8.18. Its use is thus discouraged (#14736, #15411, by Olivier Laurent, with help of Karl Palmskog).Deprecated:
identity
inductive (replaced by the equivalenteq
).Init.Logic_Type
is removed (the only remaining definitionnotT
is moved toInit.Logic
) (#15256, by Olivier Laurent).Deprecated:
P_Rmin
: use more generalRmin_case
instead (#15388, fixes #15382, by Olivier Laurent).Added: lemma
count_occ_rev
(#15397, by Olivier Laurent).Added:
Nat.EvenT
andNat.OddT
(almost the same asNat.Even
andNat.Odd
but with output inType
. Decidability of parity (with outputType
) is providedEvenT_OddT_dec
as well as induction principlesNat.EvenT_OddT_rect
andNat.OddT_EvenT_rect
(with outputType
) (#15427, by Olivier Laurent).Added: Added a proof of
sin x < x
for positivex
andx < sin x
for negativex
(#15599, by stop-cran).Added: decidability typeclass instances for Z.le, Z.lt, Z.ge and Z.gt, added lemmas Z.geb_ge and Z.gtb_gt (#15620, by Michael Soegtrop).
Added: lemmas
Rinv_inv
,Rinv_mult
,Rinv_opp
,Rinv_div
,Rdiv_opp_r
,Rsqr_div'
,Rsqr_inv'
,sqrt_inv
,Rabs_inv
,pow_inv
,powerRZ_inv'
,powerRZ_neg'
,powerRZ_mult
,cv_infty_cv_0
, which are variants of existing lemmas, but without any hypothesis (#15644, by Guillaume Melquiond).Added: a Leibniz equality test for primitive floats (#15719, by Pierre Roux, reviewed by Guillaume Melquiond).
Added: support for primitive floats in Scheme Boolean Equality (#15719, by Pierre Roux, reviewed by Hugo Herbelin).
Added: lemma
le_add_l
toNAddOrder.v
. UseNat.le_add_l
as replacement for the deprecatedPlus.le_plus_r
(#16184, by Andrej Dudenhefner).
Infrastructure and dependencies¶
Changed: Bumped lablgtk3 lower bound to 3.1.2 (#15947, by Pierre-Marie Pédrot).
Changed: Load plugins using findlib. This requires projects built with
coq_makefile
to either provide a hand writtenMETA
file or use the-generate-meta-for-package
option when applicable. As a consequenceDeclare ML Module
now uses plugin names according tofindlib
, e.g.coq-aac-tactics.plugin
.coqdep
accepts-m META
and uses the file to resolve plugin names to actual file names (#15220, fixes #7698, by Enrico Tassi).Changed: Minimum supported zarith version is now 1.11 (#15483 and #16005 and #16030, closes #15496, by Gaëtan Gilbert and Théo Zimmermann and Jason Gross).
Changed: Bump the minimum OCaml version to 4.09.0. As a consequence the minimum supported ocamlfind version is now 1.8.1 (#15947 and #16046, fixes #14260 and #16015, by Pierre-Marie Pédrot and Théo Zimmermann).
Extraction¶
Changed:
ExtrOCamlInt63
no longer extractscomparison
toint
in OCaml; the extraction ofUint63.compare
andSint63.compare
was also adapted accordingly (#15294, fixes #15280, by Li-yao Xia).Changed: Extraction from
nat
to OCamlint
uses Stdlib instead of Pervasives (#15333, by Rudy Nicolo Peterson).Changed: The empty inductive type is now extracted to OCaml empty type available since OCaml 4.07 (#15967, by Pierre Roux).
Added: More extraction definitions for division and comparison of Z and N (#15098, by Li-yao Xia).
Fixed: Type
int
in filesNumber.v
,Decimal.v
andHexadecimal.v
have been renamed tosigned_int
(together with a compatibility aliasint
) so that they can be used in extraction without conflicting with OCaml'sint
type (#13460, fixes #7017 and #13288, by Hugo Herbelin).
Changes in 8.16.1¶
Kernel¶
Fixed: conversion of Prod values in the native compiler (#16651, fixes #16645, by Pierre-Marie Pédrot).
Fixed: Coq 8.16.0 missed
SProp
check for opaque names in conversion (#16768, fixes #16752, by Hugo Herbelin).Fixed: Pass the correct environment to compute η-expansion of cofixpoints in VM and native compilation (#16845, fixes #16831, by Pierre-Marie Pédrot).
Fixed: inconsistency with conversion of primitive arrays, and associated incomplete strong normalization of primitive arrays with
lazy
(#16850, fixes #16829, by Gaëtan Gilbert, reported by Maxime Buyse and Andres Erbsen).
Commands and options¶
Fixed:
Print Assumptions
treats opaque definitions with missing proofs (as found in.vos
files, see Compiled interfaces (produced using -vos)) as axioms instead of ignoring them (#16434, fixes #16411, by Gaëtan Gilbert).
CoqIDE¶
Version 8.15¶
Summary of changes¶
Coq version 8.15 integrates many bug fixes, deprecations and cleanups as well as a few new features. We highlight some of the most impactful changes here:
The
apply with
tactic no longer renames arguments unless compatibility flagApply With Renaming
is set.Improvements to the
auto
tactic family, fixing theHint Unfold
behavior, and generalizing the use of discrimination nets.The
typeclasses eauto
tactic has a new best_effort option allowing it to return partial solutions to a proof search problem, depending on the mode declarations associated to each constraint. This mode is used by typeclass resolution during type inference to provide more precise error messages.Many commands and options were deprecated or removed after deprecation and more consistently support locality attributes.
The
Import
command is extended withimport_categories
to select the components of a module to import or not, including features such as hints, coercions, and notations.A visual Ltac debugger is now available in CoqIDE.
See the Changes in 8.15.0 section below for the detailed list of changes, including potentially breaking changes marked with Changed. Coq's reference manual for 8.15, documentation of the 8.15 standard library and developer documentation of the 8.15 ML API are also available.
Emilio Jesús Gallego Arias, Gaëtan Gilbert, Michael Soegtrop and Théo Zimmermann worked on maintaining and improving the continuous integration system and package building infrastructure.
Erik Martin-Dorel has maintained the Coq Docker images that are used in many Coq projects for continuous integration.
The opam repository for Coq packages has been maintained by Guillaume Claret, Karl Palmskog, Matthieu Sozeau and Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
The Coq Platform has been maintained by Michael Soegtrop and Enrico Tassi.
Our current maintainers are Yves Bertot, Frédéric Besson, Ali Caglayan, Tej Chajed, Cyril Cohen, Pierre Corbineau, Pierre Courtieu, Maxime Dénès, Jim Fehrle, Julien Forest, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Georges Gonthier, Benjamin Grégoire, Jason Gross, Hugo Herbelin, Vincent Laporte, Olivier Laurent, Assia Mahboubi, Kenji Maillard, Guillaume Melquiond, Pierre-Marie Pédrot, Clément Pit-Claudel, Pierre Roux, Kazuhiko Sakaguchi, Vincent Semeria, Michael Soegtrop, Arnaud Spiwack, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Anton Trunov, Li-yao Xia and Théo Zimmermann. See the Coq Team face book page for more details.
The 41 contributors to this version are Tanaka Akira, Frédéric Besson, Juan Conejero, Ali Caglayan, Cyril Cohen, Adrian Dapprich, Maxime Dénès, Stéphane Desarzens, Christian Doczkal, Andrej Dudenhefner, Jim Fehrle, Emilio Jesús Gallego Arias, Attila Gáspár, Gaëtan Gilbert, Jason Gross, Hugo Herbelin, Jasper Hugunin, Bart Jacobs, Ralf Jung, Grant Jurgensen, Jan-Oliver Kaiser, Wojciech Karpiel, Fabian Kunze, Olivier Laurent, Yishuai Li, Erik Martin-Dorel, Guillaume Melquiond, Jean-Francois Monin, Pierre-Marie Pédrot, Rudy Peterson, Clément Pit-Claudel, Seth Poulsen, Pierre Roux, Takafumi Saikawa, Kazuhiko Sakaguchi, Michael Soegtrop, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Anton Trunov and Théo Zimmerman.
The Coq community at large helped improve the design of this new version via the GitHub issue and pull request system, the Coq development mailing list coqdev@inria.fr, the coq-club@inria.fr mailing list, the Discourse forum and the Coq Zulip chat.
Version 8.15's development spanned 3 months from the release of Coq 8.14.0. Gaëtan Gilbert is the release manager of Coq 8.15. This release is the result of 384 merged PRs, closing 143 issues.
Changes in 8.15.0¶
Kernel¶
Fixed: Name clash in a computation of the type of parameters of functorial module types; this computation was provided for the purpose of clients using the algebraic form of module types such as
Print Module Type
(#15385, fixes #9555, by Hugo Herbelin).
Specification language, type inference¶
Changed:
Instance
warns about the default locality immediately rather than waiting until the instance is ready to be defined. This changes which command warns when the instance has a separate proof: theInstance
command itself warns instead of the proof closing command (such asDefined
) (#14705, by Gaëtan Gilbert).Removed: Arguments of section variables may no longer be renamed with
Arguments
(this was previously applied inconsistently) (#14573, by Gaëtan Gilbert).Added: Non-dependent implicit arguments can be provided explicitly using the syntax
(natural := term)
wherenatural
is the index of the implicit argument among all non-dependent arguments of the function, starting from 1 (#11099, by Hugo Herbelin).Added:
Succeed
, acontrol_command
that verifies that the givensentence
succeeds without changing the proof state (#14750, by Gaëtan Gilbert).Fixed: The
term.(qualid arg*)
syntax now takes into account the position of the main argumentterm
when computing the implicit arguments ofqualid
(#14606, fixes #4167, by Hugo Herbelin).Fixed: Source and target of coercions preserved by module instantiation (#14668, fixes #3527, by Hugo Herbelin).
Fixed: Made reference manual consistent with the implementation regarding the role of recursively non-uniform parameters of inductive types in the nested positivity condition (#14967, fixes #14938, by Hugo Herbelin)
Notations¶
Changed: Terms printed in error messages may be more verbose if syntactic sugar would make it appear that the obtained and expected terms only differ in existential variables (#14672, by Gaëtan Gilbert).
Removed: the
Numeral Notation
command that was renamed toNumber Notation
in 8.13 (#14819, by Pierre Roux).Removed: primitive float notations
<
,<=
and==
that were replaced by<?
,<=?
and=?
in 8.13 (#14819, by Pierre Roux).Removed: primitive integer notations
\%
,<
,<=
and==
that were replaced bymod
,<?
,<=?
and=?
in 8.13 (#14819, by Pierre Roux).Added: Include floats in the number notation mechanism (#14525, by Pierre Roux).
Added: Coercion entries and
ident
/global
entries in custom notations now respect theonly parsing
modifier (#15340, fixes #15335, by Hugo Herbelin).Fixed:
Reserved Infix
now accept further parameters in the infix notation (#14379, fixes #11402, by Hugo Herbelin).Fixed: Useless self reference when printing abbreviations declared in nested modules (#14493, fixes one part of #12777 and #14486, by Hugo Herbelin).
Fixed: anomalies with notation applied in
match
patterns when the notation have a notation variable at head (#14713, fixes #14708, by Hugo Herbelin).Fixed: Regression in parsing error reporting in case of empty custom entry (#15338, fixes #15334, by Hugo Herbelin).
Tactics¶
Changed:
apply with
does not rename arguments unless using compatibility flagApply With Renaming
(#13837, fixes #13759, by Gaëtan Gilbert).Porting hint: if the renaming is because of a goal variable (eg
intros x; apply foo with (x0 := bar)
whereAbout foo.
says the argument is calledx
) it is probably caused by an interaction with implicit arguments andapply @foo with (x := bar)
will usually be a backwards compatible fix.Changed:
Hint Unfold
in discriminated databases now respects its specification, namely that a constant may be unfolded only when it is the head of the goal. The previous behavior was to perform unfolding on any goal, without any limitation.An unexpected side-effect of this was that a database that contained
Unfold
hints would sometimes trigger silent strong βι-normalization of the goal. Indeed,unfold
performs such a normalization regardless of the presence of its argument in the goal. This does introduce a bit of backwards incompatibility, but it occurs in very specific situations and is easily circumvented. Since by default hint bases are not discriminated, it means that incompatibilities are typically observed when adding unfold hints to the typeclass database.In order to recover the previous behavior, it is enough to replace instances of
Hint Unfold foo.
withHint Extern 4 => progress (unfold foo).
. A less compatible but finer-grained change can be achieved by only adding the missing normalization phase withHint Extern 4 => progress (lazy beta iota).
(#14679, fixes #14874, by Pierre-Marie Pédrot).Changed: Correctly consider variables without a body to be rigid for the pattern recognition algorithm of discriminated hints (#14722, by Pierre-Marie Pédrot).
Changed: Use discrimination nets for goals containing evars in all
auto
tactics. It essentially makes the behavior of undiscriminated databases to be the one of discriminated databases where all constants are considered transparent. This may be incompatible with previous behavior in very rare cases (#14848, by Pierre-Marie Pédrot).Changed: The
choice
strategy forrewrite_strat
is now of arbitrary arity (#14989, fixes #6109, by Gaëtan Gilbert).Changed: The
exact
tactic now takes auconstr
as argument instead of an ad-hoc one. In very rare cases, this can change the order of resolution of dependent evars when used over several goals at once (#15171, by Pierre-Marie Pédrot).Changed:
cbn
interprets the combination of the!
and/
modifiers (fromArguments
) to mean "unfold as soon as all arguments before the/
are provided and all arguments marked with!
reduce to a constructor". This makes it unfold more often than without the/
when all arguments are provided. Previously adding/
would only prevent unfolding when insufficient arguments are provided without adding new unfoldings.Note that this change only takes effect in default mode (as opposed to when
simpl nomatch
was used) (#15204, fixes #4555 and #7674, by Gaëtan Gilbert).Removed: the deprecated new auto tactic (#14527, by Pierre-Marie Pédrot).
Removed: deprecated syntax for
instantiate
using capitalizedValue
orType
(#15193, by Gaëtan Gilbert).Removed: deprecated
autoapply ... using
syntax forautoapply
(#15194, by Gaëtan Gilbert).Deprecated: the
bfs eauto
tactic. Since its introduction it has behaved exactly like theeauto
tactic. Usetypeclasses eauto
with thebfs
flag instead (#15314, fixes #15300, by Pierre-Marie Pédrot).Added: The
zify
tactic can now recognizePos.Nsucc_double
,Pos.Ndouble
,N.succ_double
,N.double
,N.succ_pos
,N.div2
,N.pow
,N.square
, andZ.to_pos
. Moreover, importing moduleZifyBool
lets it recognizePos.eqb
,Pos.leb
,Pos.ltb
,N.eqb
,N.leb
, andN.ltb
(#10998, by Kazuhiko Sakaguchi).Added: best_effort option to
typeclasses eauto
, to return a partial solution to its initial proof-search problem. The goals that can remain unsolved are determined according to the modes declared for their head (seeHint Mode
). This is used by typeclass resolution during type inference to provide more informative error messages (#13952, fixes #13942 and #14125, by Matthieu Sozeau).Added: A new
Keep Equalities
table to selectively control the preservation of subterm equalities for theinjection
tactic. It allows a finer control than the boolean flagKeep Proof Equalities
that acts globally (#14439, by Pierre-Marie Pédrot).Added:
simple congruence
tactic which works likecongruence
but does not unfold definitions (#14657, fixes #13778 and #5394 and #13189, by Andrej Dudenhefner).Added: Small enhancement of unification in the presence of local definitions (#14673, fixes #4415, by Hugo Herbelin).
Added:
dfs
option intypeclasses eauto
to use depth-first search (#14693, fixes #13859, by Ali Caglayan).Fixed: More flexible hypothesis specialization in
congruence
(#14650, fixes #14651 and #14662, by Andrej Dudenhefner).Fixed: Added caching to congruence initialization to avoid quadratic runtime (#14683, fixes #5548, by Andrej Dudenhefner).
Fixed: Correctly handle matching up to η-expansion in discriminated hints (#14732, fixes #14731, by Pierre-Marie Pédrot).
Fixed: Old unification understands some inductive cumulativity (#14758, fixes #14734 and #6976, by Gaëtan Gilbert).
Fixed: The
clear dependent
tactic now does not backtrack internally, preventing an exponential blowup (#14984, fixes #11689, by Pierre-Marie Pédrot).Fixed:
setoid_rewrite
now works when the rewriting lemma has non dependent arguments and rewriting under binders (#14986, fixes #5369, by Gaëtan Gilbert).Fixed: Regression in 8.14.0 and 8.14.1 with action pattern
%
inas
clause of tacticspecialize
(#15245, fixes #15244, by Hugo Herbelin).
Tactic language¶
SSReflect¶
Changed: rewrite generates subgoals in the expected order (side conditions first, by default) also when rewriting with a setoid relation (#14314, fixes #5706, by Enrico Tassi).
Removed: The ssrsearch plugin and the ssr Search command (#13760, by Jim Fehrle).
Added: port the additions made to
ssrbool.v
in math-comp PR #757, namelyreflect
combinatorsnegPP
,orPP
,andPP
andimplyPP
(#15059, by Christian Doczkal).Fixed: SSR patterns now work with primitive values such as ints, floats or arrays (#14660, fixes #12770, by Juan Conejero).
Fixed: A bug where
suff
would fail due to use ofapply
under the hood (#14687, fixes #14678, by Ali Caglayan helped by Enrico Tassi).
Commands and options¶
Changed:
About
andPrint
now display all known argument names (#14596, grants #13830, by Hugo Herbelin).Changed:
Typeclasses Transparent
andTypeclasses Opaque
support#[local]
,#[export]
and#[global]
attributes (#14685, fixes #14513, by Gaëtan Gilbert).Changed: In extraction to OCaml, empty types in
Type
(such asEmpty_set
) are now extracted to an abstract type (empty by construction) rather than to the OCaml'sunit
type (#14802, fixes a remark at #14801, by Hugo Herbelin).Changed: Closed modules now live in a separate namespace from open modules and sections (#15078, fixes #14529, by Gaëtan Gilbert).
Removed: boolean attributes
monomorphic
,noncumulative
andnotemplate
that were replaced bypolymorphic=no
,cumulative=no
andtemplate=no
in 8.13 (#14819, by Pierre Roux).Removed: command
Grab Existential Variables
that was deprecated in 8.13. UseUnshelve
that is mostly equivalent, up to the reverse order of the resulting subgoals (#14819, by Pierre Roux).Removed: command
Existential
that was deprecated in 8.13. UseUnshelve
andexact
(#14819, by Pierre Roux).Removed: the
-outputstate
command line argument and the corresponding vernacular commandsWrite State
andRestore State
(#14940, by Pierre-Marie Pédrot)Deprecated: ambiguous
Proof using
andCollection
usage (#15056, fixes #13296, by Wojciech Karpiel).Deprecated:
Universal Lemma Under Conjunction
flag that was introduced for compatibility with Coq versions prior to 8.4 (#15272, by Théo Zimmermann).Deprecated: using
Hint Cut
,Hint Mode
,Hint Transparent
,Hint Opaque
,Typeclasses Transparent
orTypeclasses Opaque
without an explicit locality outside sections. (#14697, by Pierre-Marie Pédrot, and #14685, by Gaëtan Gilbert)Added: The
Mangle Names Light
flag, which changes the behavior ofMangle Names
. For example, the namefoo
becomes_0
withMangle Names
, but withMangle Names Light
set, it will become_foo
(#14695, fixes #14548, by Ali Caglayan).Added: The
Hint Cut
,Hint Mode
,Hint Transparent
,Hint Opaque
,Typeclasses Transparent
andTypeclasses Opaque
commands now accept thelocal
,export
andglobal
locality attributes inside sections. With either attribute, the commands will trigger thenon-local-section-hint
warning if the arguments refer to local section variables (#14697, by Pierre-Marie Pédrot, and #14685, fixes #14513, by Gaëtan Gilbert).Added:
projections(primitive)
attribute to make a record use primitive projections (#14699, fixes #13150, by Ali Caglayan).Added: Syntax for
import_categories
providing selective import of module components (egImport(notations) M
(#14892, by Gaëtan Gilbert).Added:
Search
understands modifierin
as an alias ofinside
(#15139, fixes #14930, by Gaëtan Gilbert). This is intended to ease transition for ssreflect Search users.Fixed: interaction of Program's obligation state and modules and sections: obligations started in a parent module or section are not available to be solved until the submodules and subsections are closed (#14780, fixes #14446, by Gaëtan Gilbert).
Fixed:
Eval
andCompute
now beta-iota-simplify the type of the result, likeCheck
does (#14901, fixes #14899, by Hugo Herbelin)
Command-line tools¶
Changed: Coqdoc options
--coqlib
and--coqlib_path
have been renamed to--coqlib_url
and--coqlib
to make them more consistent with flags used by other Coq executables (#14059, by Emilio Jesus Gallego Arias).Changed: Syntax of
_CoqProject
files:-arg
is now handled by coq_makefile and not bymake
. Unquoted#
now start line comments (#14558, by Stéphane Desarzens, with help from Jim Fehrle and Enrico Tassi).Changed:
Require
now selects files whose logical name exactly matches the required name, making it possible to unambiguously select a given file: if several-Q
or-R
options bind the same logical name to a different file, the option appearing last on the command line takes precedence. Moreover, it is now an error to require a file using a partial logical name which does not resolve to a non-ambiguous path (#14718, by Hugo Herbelin).Changed:
coq_makefile
now declares variableCOQBIN
to avoid warnings inmake --warn
mode (#14787, by Clément Pit-Claudel).Changed:
coqchk
respects theKernel Term Sharing
flag instead of forcing it on (#14957, by Gaëtan Gilbert)Removed: These options of coq_makefile:
-extra
,-extra-phony
,-custom
,-no-install
,-install
,-no-opt
,-byte
. Support for subdirectories is also removed (#14558, by Stéphane Desarzens, with help from Jim Fehrle and Enrico Tassi).Added: coq_makefile now takes the
-docroot
option as alternative to theINSTALLCOQDOCROOT
variable (#14558, by Stéphane Desarzens, with help from Jim Fehrle and Enrico Tassi).Fixed: Various
coqdep
issues with theFrom
clause ofRequire
and a few inconsistencies betweencoqdep
andcoqc
disambiguation ofRequire
(#14718, fixes #11631 and #14539, by Hugo Herbelin).Fixed:
coq_makefile
has improved logic when dealing with incorrect_CoqProject
files (#13541, fixes #9319, by Fabian Kunze).Fixed:
coqdep
was confusing periods occurring in comments with periods ending Coq sentences (#14996, fixes #7393, by Hugo Herbelin).
CoqIDE¶
Changed: CoqIDE unicode keys for brackets (e.g.
langle
) now bind to unicode mathematical symbols rather than unicode CJK brackets (#14452, by Bart Jacobs).Changed: All occurrences of the name
CoqIde
toCoqIDE
. This may cause issues with installing and uninstalling desktop icons, causing apparent duplicates (#14696, fixes #14310, by Ali Caglayan).Added: Initial version of a visual debugger in CoqIDE. Supports setting breakpoints visually and jumping to the stopping point plus continue, step over, step in and step out operations. Displays the call stack and variable values for each stack frame. Currently only for Ltac. See the documentation here (#14644, fixes #13967, by Jim Fehrle)
Fixed: It is now possible to deactivate the unicode completion mechanism in CoqIDE (#14863, by Pierre-Marie Pédrot).
Standard library¶
Changed: Permutation-related Proper instances are now at default priority instead of priority
10
(#14574, fixes #14571, by Gaëtan Gilbert).Changed: The new type of
epsilon_smallest
is(exists n : nat, P n) -> { n : nat | P n /forall k, P k -> n <= k }
. Here the minimality ofn
is expressed byforall k, P k -> n <= k
corresponding to the intuitive meaning of minimality "the others are greater", whereas the previous version used the negative equivalent formulationforall k, k < n -> ~P k
. Scripts usingepsilon_smallest
can easily be adapted using lemmasle_not_lt
andlt_not_le
from the standard library (#14601, by Jean-Francois Monin).Changed:
ltb
andleb
functions forascii
, into comparison-based definition (#14234, by Yishuai Li).Removed: the file
Numeral.v
that was replaced byNumber.v
in 8.13 (#14819, by Pierre Roux).Removed: some
*_invol
functions that were renamed*_involutive
for consistency with the remaining of the stdlib in 8.13 (#14819, by Pierre Roux).Deprecated:
frexp
andldexp
inFloatOps.v
, renamedZ.frexp
andZ.ldexp
(#15085, by Pierre Roux).Added: A proof that incoherent equivalences can be adjusted to adjoint equivalences in
Logic.Adjointification
(#13408, by Jasper Hugunin).Added:
ltb
andleb
functions forstring
, and some lemmas about them;Added: simple non dependent product
slexprod
inRelations/Relation_Operators.v
and its proof of well-foundnesswf_slexprod
inWellfounded/Lexicographic_Product.v
(#14809, by Laurent Thery).Added: The notations
(x; y)
,x.1
,x.2
for sigT are now exported and available afterImport SigTNotations.
(#14813, by Laurent Théry).Added: The function
sigT_of_prod
turns a pairA * B
into{_ : A & B}
. Its inverse function isprod_of_sigT
. This is shown by theoremssigT_prod_sigT
andprod_sigT_prod
(#14813, by Laurent Théry).Fixed:
split_combine
lemma for lists, making it usable (#14458, by Yishuai Li).
Infrastructure and dependencies¶
Changed: Coq's continuous integration now provides a more accessible Windows installer artifact in the "Checks" GitHub tab, both for pull requests and the
master
branch.This facilitates testing Coq's bleeding edge builds on Windows, and should be more reliable than the previous setup (#12425, by Emilio Jesus Gallego Arias).
Changed: Coq's
./configure
script has gone through a major cleanup. In particular, the following options have been removed:-force-caml-version
,-force-findlib-version
: Coq won't compile with OCaml or findlib lower than the required versions;-vmbyteflags
,-custom
,-no-custom
: linking options for toplevels are now controlled intopbin/dune
;-ocamlfind
: Coq will now use the toolchain specified in the Dune configuration; this can be controlled using the workspaces feature;-nodebug
: Coq will now follow the standard, which is to always pass-g
to OCaml; this can be modified using a custom Dune workspace;-flambda-opts
: compilation options are now set in Coq's rootdune
file, can be updated using a custom Dune workspace;-local
,-bindir
,-coqdocdir
,-annotate
,-camldir
,-profiling
: these flags were deprecated in 8.14, and are now removed.
Moreover, the
-annot
and-bin-annot
flags only take effect to setcoq-makefile
's defaults (#14189, by Emilio Jesus Gallego Arias).Changed: Configure will now detect the Dune version, and will correctly pass
-etcdir
and-docdir
to the install procedure if Dune >= 2.9 is available. Note that the-docdir
configure option now refers to root path for documentation. If you would like to install Coq documentation infoo/coq
, use-docdir foo
(#14844, by Emilio Jesus Gallego Arias).Changed: OCaml 4.13 is now officially supported (#14879, by Emilio Jesus Gallego Arias)
Changed: Sphinx 3.0.2 or above is now required to build the reference manual (#14963, by Théo Zimmermann)
Extraction¶
Changed: replaced
Big
module withBig_int_Z
functions fromzarith
.OCaml code extracted with the following modules should be linked to the Zarith library.
ExtrOcamlNatBigInt
ExtrOcamlZBigInt
Removed
ExtrOcamlBigIntConv
module.(#8252, by Yishuai Li).
Fixed: compilation errors in ExtrOcamlString and ExtrOcamlNativeString (#15075, fixes #15076, by Yishuai Li).
Changes in 8.15.1¶
Kernel¶
Fixed: cases of incompletenesses in the guard condition for fixpoints in the presence of cofixpoints or primitive projections (#15498, fixes #15451, by Hugo Herbelin).
Fixed: inconsistency when using module subtyping with squashed inductives (#15839, fixes #15838 (reported by Pierre-Marie Pédrot), by Gaëtan Gilbert).
Notations¶
Tactics¶
Fixed:
rewrite_strat
regression in 8.15.0 related toTransitive
instances (#15577, fixes #15568, by Gaëtan Gilbert).Fixed: When
setoid_rewrite
succeeds in rewriting at some occurrence but the resulting equality is the identity, it now tries rewriting in subterms of that occurrence instead of giving up (#15612, fixes #8080, by Gaëtan Gilbert).Fixed: Ill-typed goals created by
clearbody
in the presence of transitive dependencies in the body of a hypothesis (#15634, fixes #15606, by Hugo Herbelin).Fixed:
cbn
knows to refold fixpoints whenArguments
with/
and!
was used (#15653, fixes #15567, by Gaëtan Gilbert).
Command-line tools¶
Fixed: a bug where
coqc -vok
was not creating an empty '.vok' file (#15745, by Ramkumar Ramachandra).
CoqIDE¶
Fixed: Line numbers shown in the Errors panel were incorrect; they didn't match the error locations in the script panel (#15532, fixes #15531, by Jim Fehrle).
Fixed: anomaly when using proof diffs with no focused goal (#15633, fixes #15578, by Jim Fehrle).
Fixed: Attempted edits to the processed part of a buffer while Coq is busy processing a request are now ignored to ensure "processed" highlighting is accurate (#15714, fixes #15733 and #15675 and #15725, by Jim Fehrle).
Miscellaneous¶
Changes in 8.15.2¶
Tactics¶
Added:
intuition
anddintuition
useTauto.intuition_solver
(defined asauto with *
) instead of hardcodingauto with *
. This makes it possible to change the default solver withLtac Tauto.intuition_solver ::= ...
(#15866, fixes #7725, by Gaëtan Gilbert).Fixed: uncaught exception
UnableToUnify
with bidirectionality hints (#16066, fixes #16063, by Gaëtan Gilbert).
CoqIDE¶
Standard library¶
Version 8.14¶
Summary of changes¶
Coq version 8.14 integrates many usability improvements, as well as an important change in the core language. The main changes include:
The internal representation of
match
has changed to a more space-efficient and cleaner structure, allowing the fix of a completeness issue with cumulative inductive types in the type-checker. The internal representation is now closer to the user-level view ofmatch
, where the argument context of branches and the inductive bindersin
andas
do not carry type annotations.A new
coqnative
binary performs separate native compilation of libraries, starting from a.vo
file. It is supported bycoq_makefile
.Improvements to typeclasses and canonical structure resolution, allowing more terms to be considered as classes or keys.
More control over notations declarations and support for primitive types in string and number notations.
Removal of deprecated tactics, notably
omega
, which has been replaced by a greatly improvedlia
, along with many bug fixes.New Ltac2 APIs for interaction with Ltac1, manipulation of inductive types and printing.
Many changes and additions to the standard library in the numbers, vectors and lists libraries. A new signed primitive integers library
Sint63
is available in addition to the unsignedUint63
library.
See the Changes in 8.14.0 section below for the detailed list of changes, including potentially breaking changes marked with Changed. Coq's reference manual, documentation of the standard library and developer documentation of the ML API are also available.
Emilio Jesús Gallego Arias, Gaëtan Gilbert, Michael Soegtrop and Théo Zimmermann worked on maintaining and improving the continuous integration system and package building infrastructure.
Erik Martin-Dorel has maintained the Coq Docker images that are used in many Coq projects for continuous integration.
The opam repository for Coq packages has been maintained by Guillaume Claret, Karl Palmskog, Matthieu Sozeau and Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
The Coq Platform has been maintained by Michael Soegtrop and Enrico Tassi.
Our current maintainers are Yves Bertot, Frédéric Besson, Ali Caglayan, Tej Chajed, Cyril Cohen, Pierre Corbineau, Pierre Courtieu, Maxime Dénès, Jim Fehrle, Julien Forest, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Georges Gonthier, Benjamin Grégoire, Jason Gross, Hugo Herbelin, Vincent Laporte, Olivier Laurent, Assia Mahboubi, Kenji Maillard, Guillaume Melquiond, Pierre-Marie Pédrot, Clément Pit-Claudel, Pierre Roux, Kazuhiko Sakaguchi, Vincent Semeria, Michael Soegtrop, Arnaud Spiwack, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Anton Trunov, Li-yao Xia and Théo Zimmermann. See the Coq Team face book page for more details.
The 54 contributors to this version are Reynald Affeldt, Arthur Azevedo de Amorim, Yves Bertot, Frédéric Besson, Lasse Blaauwbroek, Ana Borges, Ali Caglayan, Cyril Cohen, Pierre Courtieu, Maxime Dénès, Stéphane Desarzens, Andrej Dudenhefner, Jim Fehrle, Yannick Forster, Simon Friis Vindum, Gaëtan Gilbert, Jason Gross, Samuel Gruetter, Stefan Haan, Hugo Herbelin, Jasper Hugunin, Emilio Jesús Gallego Arias, Jacques-Henri Jourdan, Ralf Jung, Jan-Oliver Kaiser, Fabian Kunze, Vincent Laporte, Olivier Laurent, Yishuai Li, Barry M. Trager, Kenji Maillard, Erik Martin-Dorel, Guillaume Melquiond, Isaac Oscar Gariano, Pierre-Marie Pédrot, Rudy Peterson, Clément Pit-Claudel, Pierre Roux, Takafumi Saikawa, Kazuhiko Sakaguchi, Gabriel Scherer, Vincent Semeria, shenlebantongying, Avi Shinnar, slrnsc, Michael Soegtrop, Matthieu Sozeau, Enrico Tassi, Hendrik Tews, Anton Trunov, Karolin Varner, Li-yao Xia, Beta Ziliani and Théo Zimmermann.
The Coq community at large helped improve the design of this new version via the GitHub issue and pull request system, the Coq development mailing list coqdev@inria.fr, the coq-club@inria.fr mailing list, the Discourse forum and the Coq Zulip chat.
Version 8.14's development spanned 9 months from the release of Coq 8.13.0. Guillaume Melquiond is the release manager of Coq 8.14. This release is the result of 522 merged PRs, closing ~150 issues.
Changes in 8.14.0¶
Kernel¶
Changed: The term representation of pattern-matchings now uses a compact form that provides a few static guarantees such as eta-expansion of branches and return clauses and is usually more efficient. The most visible user change is that for the time being, the
destruct
tactic and its variants generate dummy cuts (β redexes) in the branches of the generated proof. This can also generate very uncommon backwards incompatibilities, such as a change of occurrence numbering for subterms, or breakage of unification in complex situations involving pattern-matchings whose underlying inductive type declares let-bindings in parameters, arity or constructor types. For ML plugin developers, an in-depth description of the new representation, as well as porting tips, can be found in dev/doc/case-repr.md (#13563, fixes #3166, by Pierre-Marie Pédrot).Changed: Linking of native-code libraries used by
native_compute
is now delayed until an actual call to thenative_compute
machinery is performed. This should make Coq more responsive on some systems (#13853, fixes #13849, by Guillaume Melquiond).Removed: The ability to change typing flags inside sections to prevent exploiting a weakness in
Print Assumptions
(#14395, fixes #14317, by Gaëtan Gilbert).
Specification language, type inference¶
Changed: The hints mode
!
matches a term iff the applicative head is not an existential variable. It now also matches projections applied to any term or amatch
on any term (#14392, by Matthieu Sozeau).Removed: The little used
:>
type cast, which was only interpreted in Program-mode (#13911, by Jim Fehrle and Théo Zimmermann).Added: Enable canonical
fun _ => _
projections, see Canonical Structures for details (#14041, by Jan-Oliver Kaiser and Pierre Roux, reviewed by Cyril Cohen and Enrico Tassi).Added:
Canonical Structure
declarations now accept dependent function typesforall _, _
as keys (#14386, by Jan-Oliver Kaiser and Kazuhiko Sakaguchi).Added: Ability to declare primitive projections as class, for dependent typeclass resolutions (#9711, fixes #12975, by Matthieu Sozeau).
Fixed: Multiple printing of same warning about unused variables catching several cases (#14261, fixes #14207, by Hugo Herbelin).
Fixed: Constants
id
andnot
were unduly set opaque in some parts of the unification algorithm (#14371, fixes #14374, by Hugo Herbelin).
Notations¶
Changed: Flag
Printing Notations
no longer controls whether strings and numbers are printed raw (#13840, by Enrico Tassi).Changed: The error
Argument X was previously inferred to be in scope XXX_scope but is here used in YYY_scope.
is now the warning[inconsistent-scopes,syntax]
and can be silenced by specifying the scope of the argument (#13965, by Enrico Tassi).Removed: Decimal-only number notations which were deprecated in 8.12 (#13842, by Pierre Roux).
Added:
Number Notation
andString Notation
now support parsing and printing of primitive floats, primitive arrays and type constants of primitive types (#13519, fixes #13484 and #13517, by Fabian Kunze, with help of Jason Gross)Added: Flag
Printing Raw Literals
to control whether strings and numbers are printed raw (#13840, by Enrico Tassi).Added: Let the user specify a scope for abbreviation arguments, e.g.
Notation abbr X := t (X in scope my_scope)
(#13965, by Enrico Tassi).Added: Look-ahead of tokens is changed from sequential to tree-based, allowing more automatic rule factorizations in notations (#14070, by Hugo Herbelin).
Fixed: Non-local custom entries survive module closing and are declared when a file is Required (#14183, fixes #13654, by Gaëtan Gilbert).
Fixed:
ident
modifier in custom entry notations gave fatal errors at printing time (#14257, fixes #14211, by Hugo Herbelin).Fixed: Anomaly when overriding a notation with different applicability in
match
patterns (#14377, fixes #13966, by Hugo Herbelin).
Tactics¶
Changed: More systematic checks that occurrences of an
at
clause are valid in tactics such asrewrite
orpattern
(#13568, fixes #13566, by Hugo Herbelin).Removed:
fail
andgfail
, which formerly accepted negative values as a parameter, now give syntax errors for negative values (#13469, by Jim Fehrle).Removed: Deprecated flag
Bracketing Last Introduction Pattern
affecting the behavior of trailing disjunctive introduction patterns is definitively removed (#13509, by Hugo Herbelin).Removed: The
omega
tactic (deprecated in 8.12) and four* Omega *
flags. Uselia
instead (#13741, by Jim Fehrle, who addressed the final details, building on much work by Frédéric Besson, who greatly improvedlia
, Maxime Dénès, Vincent Laporte and with the help of many package maintainers, among others).Removed: convert_concl_no_check. Use
change_no_check
instead (#13761, by Jim Fehrle).Removed: double induction tactic. Replace
double induction ident ident
withinduction ident; induction ident
(orinduction ident ; destruct ident
depending on the exact needs). Replacedouble induction natural1 natural2
withinduction natural1; induction natural3
wherenatural3
is the result ofnatural2 - natural1
(#13762, by Jim Fehrle).Deprecated: In
change
andchange_no_check
, theat ... with ...
form is deprecated. Usewith ... at ...
instead. Forat ... with ... in H |-
, usewith ... in H at ... |-
(#13696, by Jim Fehrle).Deprecated: The micromega option
Simplex
, which is currently set by default (#13781, by Frédéric Besson).Deprecated: the undocumented
new auto
tactic (#14528, by Pierre-Marie Pédrot).Added:
lia
supports the boolean operatorBool.implb
(#13715, by Frédéric Besson).Added:
zify
(lia
/nia
) support fordiv
,mod
,pow
forNat
(viaZifyNat
module) andN
(viaZifyN
module). The signature ofZ_div_mod_eq_full
has no assumptions (#14037, fixes #11447, by Andrej Dudenhefner, Jason Gross, and Frédéric Besson).Added: Ltac2 now has a
unify
tactic (#14089, fixes #14083, by Samuel Gruetter).Added:
inversion_sigma
can now be applied to a specified hypothesis and additionally supports intropatterns, so it can be used much likeinduction
andinversion
. Additionally,inversion_sigma
now supports the typesex
(exists x : A, P x
) andex2
(exists2 x : A, P x & Q x
) in cases where the first argumentA
is aProp
(#14174, by Jason Gross).Added:
zify
(lia
/nia
) support forSint63
(#14408, by Ana Borges, with help from Frédéric Besson).Fixed: Possible collision between a user-level name and an internal name when using the
%
introduction pattern (#13512, fixes #13413, by Hugo Herbelin).Fixed:
simpl
andhnf
now reduce primitive functions on primitive integers, floats and arrays (#13699, fixes #13579, by Pierre Roux).Fixed: Setoid rewriting now remembers the (invisible) binder names of non-dependent product types. SSReflect's rewrite tactic expects these names to be retained when using
rewrite foo in H
. This also fixes SSRrewrite foo in H *
erroneously revertingH
(#13882, fixes #12011, by Gaëtan Gilbert).Fixed: Properly expand projection parameters in hint discrimination nets. (#14033, fixes #9000, #14009, by Pierre-Marie Pédrot).
Fixed: anomalies caused by empty strings in Ltac notations are now errors (#14378, fixes #14124, by Hugo Herbelin).
Fixed: Print a message instead of a Diff_Failure anomaly when old and new goals can't be matched; show the goal without diff highlights (#14457, fixes #14425, by Jim Fehrle).
Fixed: Anomaly of
destruct
on terms with dependent variables unused in goal (#15099, fixes #11504 and #14090, by Lasse Blaauwbroek and Hugo Herbelin).Fixed: Correct convertibility of multiple terms selected by patterns in tactics such as
set
when these terms have subterms inSProp
(#14610, fixes #14609, by Hugo Herbelin).
Tactic language¶
Changed: Renamed Ltac2
Bool.eq
intoBool.equal
for uniformity. The old function is now a deprecated alias (#14128, by Pierre-Marie Pédrot).Added: A
printf
macro to Ltac2. It can be made accessible by importing theLtac2.Printf
module. See the documentation there for more information (#13236, fixes #10108, by Pierre-Marie Pédrot).Added: A function
Ltac1.lambda
allowing to embed Ltac2 functions into Ltac1 runtime values (#13442, fixes #12871, by Pierre-Marie Pédrot).Added: Ltac2 commands defining terms now accept the
deprecated
attribute (#13774, fixes #12317, by Pierre-Marie Pédrot).Added: Allow the presence of type casts for function return values, let bindings and global definitions in Ltac2 (#13914, by Pierre-Marie Pédrot).
Added: The Ltac2 API
Ltac2.Ind
for manipulating inductive types (#13920, fixes #10095, by Pierre-Marie Pédrot).Added: Allow scope delimiters in Ltac2
open_constr:(...)
quotation (#13939, fixes #12806, by Pierre-Marie Pédrot).Added: A FFI to convert between Ltac1 and Ltac2 identifiers (#13997, fixes #13996, by Pierre-Marie Pédrot).
Added: Lazy evaluating boolean operators
lazy_and
,lazy_or
,lazy_impl
and infix notations&&
and||
to the Ltac2Bool.v
library l (#14081, fixes #13964, by Michael Soegtrop).Fixed: Ltac2 notations now correctly take into account their assigned level (#14094, fixes #11866, by Pierre-Marie Pédrot).
SSReflect¶
Commands and options¶
Changed:
Hint Rewrite
now supports locality attributes (includingexport
) like other Hint commands (#13725, fixes #13724, by Gaëtan Gilbert).Changed: In
Record
, alpha-rename the variable associated with the record to avoid alpha-renaming parameters of projections (#13852, fixes #13727, by Li-yao Xia).Changed: Improve the
Coercion
command to reduce the number of ambiguous paths to report. A pair of multiple inheritance paths that can be reduced to smaller adjoining pairs will not be reported as ambiguous paths anymore (#13909, by Kazuhiko Sakaguchi).Changed: The printing order of
Print Classes
andPrint Graph
, due to the changes for the internal tables of coercion classes and coercion paths (#13912, by Kazuhiko Sakaguchi).Removed: The Hide Obligations flag, deprecated in 8.12 (#13758, by Jim Fehrle).
Removed: SearchHead command. Use the
headconcl:
clause ofSearch
instead (#13763, by Jim Fehrle).Removed:
Show Zify Spec
,Add InjTyp
and 11 similarAdd *
commands. ForShow Zify Spec
, useShow Zify UnOpSpec
orShow Zify BinOpSpec
instead. ForAdd *
,Use Add Zify *
intead ofAdd *
(#13764, by Jim Fehrle).Deprecated: Like hints, typeclass instances added outside of sections without an explicit locality now generate a deprecation warning. See Hint (#14208, fixes #13562, by Pierre-Marie Pédrot).
Deprecated: the
Regular Subst Tactic
flag (#14336, by Pierre-Marie Pédrot).Added:
Debug
to control debug messages, functioning similarly to the warning system (#13202, by Maxime Dénès and Gaëtan Gilbert). The following flags have been converted (such thatSet Flag
becomesSet Debug "flag"
):Debug Unification
tounification
Debug HO Unification
toho-unification
Debug Tactic Unification
totactic-unification
Congruence Verbose
tocongruence
Debug Cbv
tocbv
Debug RAKAM
toRAKAM
Debug Ssreflect
tossreflect
Added: The Ltac2 grammar can now be printed using the Print Grammar ltac2 command (#14093, fixes #14092, by Pierre-Marie Pédrot).
Added:
Instance
now accepts theexport
locality attribute (#14148, by Pierre-Marie Pédrot).Fixed: extraction failure of a parameterized type in
Prop
exported in an module interface as an assumption inType
(#14102, fixes #14100, by Hugo Herbelin).Fixed: Print Assumptions now treats delayed opaque proofs generated by vos compilation as if they were axioms (#14382, fixes #13589, by Pierre-Marie Pédrot).
Fixed: Incorrect de Bruijn index handling in vernac class declaration, preventing users from marking existing instances of existing classes which are primitive projections (#14664, fixes #14652, by Ali Caglayan and Hugo Herbelin).
Command-line tools¶
Changed:
coqc
now enforces that at most a single.v
file can be passed in the command line. Support for multiple.v
files in the form ofcoqc f1.v f2.v
didn't properly work in 8.13, tho it was accepted (#13876, by Emilio Jesus Gallego Arias).Changed:
coqdep
now reports an error if files specified on the command line don't exist or if it encounters unreadable files. Unknown options now generate a warning. Previously these conditions were ignored (#14024, fixes #14023, by Hendrik Tews).Changed: Makefiles produced by
coq_makefile
now use.DELETE_ON_ERROR
(#14238, by Gaëtan Gilbert).Removed: Previously deprecated command line options
-sprop-cumulative
and-input-state
and its alias-is
(#13822, by Gaëtan Gilbert).Added:
coq_makefile
-madeMakefile
s now support inclusion of a.local-late
file at the end, allowing the user to access more variables (#12411, fixes #10912, by Jason Gross).Fixed: Failure of extraction in the presence of inductive types with local definitions in parameters (#13624, fixes #13581, by Hugo Herbelin).
Fixed: File name was missing in coqdoc error position reporting (#14285, fixes #14283, by Arthur Charguéraud and Hugo Herbelin).
Native Compilation¶
Changed:
coq_makefile
now uses thecoqnative
binary to generate native compilation files. Project files also understand directly the-native-compiler
flag without having to wrap it with-arg
(#14265, by Pierre-Marie Pédrot).Deprecated: the
-native-compiler
option for coqc. It is now recommended to use the Split compilation of native computation files binary instead to generate native compilation files ahead of time (#14309, by Pierre-Marie Pédrot).Added: A standalone
coqnative
binary that performs native compilation out ofvo
files, allowing to split library compilation from native compilation. See Split compilation of native computation files. The hybrid build system was adapted to perform a split compilation on the stdlib (#13287, by Pierre-Marie Pédrot).
CoqIDE¶
Added: Ltac debugger support in CoqIDE (see
Ltac Debug
). Debugger output and prompts appear in the Messages panel (#13783, by Jim Fehrle and Emilio J. Gallego Arias).Added: Shift-return in the Find dialog now searches backwards (#13810, by slrnsc).
Standard library¶
Changed: Minor Changes to
Rpower
: Generalizesexp_ineq1
to hold for all non-zero numbers. Addsexp_ineq1_le
, which holds for all reals (but is a<=
instead of a<
) (#13582, by Avi Shinnar and Barry Trager, with help from Laurent Théry).Changed: set
n mod 0 = n
uniformly fornat
,N
,Z
,int63
,sint63
,int31
such thatm = (m / n) * n + (m mod n)
holds (also forn = 0
)Warning
code that relies on
n mod 0 = 0
will break; for compatibility with bothn mod 0 = n
andn mod 0 = 0
you can usen mod 0 = ltac:(match eval hnf in (1 mod 0) with |0 => exact 0 |_ => exact n end)
(#14086, by Andrej Dudenhefner with help of Guillaume Melquiond, Jason Gross, and Kazuhiko Sakaguchi).
Changed: The standard library now contains a more complete theory of equality on types of the form
exists x : A, P x
andexists2 x : A, P x & Q x
when we haveA : Prop
. To bring this theory more in line with the existing theory about sigma types,eq_ex_uncurried
,eq_ex2_uncurried
,eq_ex
,eq_ex2
,eq_ex_hprop
,eq_ex2_hprop
have been renamed intoeq_ex_intro_uncurried
,eq_ex_intro2_uncurried
,eq_ex_intro
,eq_ex_intro2
,eq_ex_intro_hprop
,eq_ex_intro2_hprop
respectively and the implicit status of these lemmas has changed slightly (#14174, by Jason Gross).Changed Moved 39 lemmas and notations about the rationals
Q
from the constructive reals private filetheories/Reals/Cauchy/QExtra.v
to appropriate files intheories/QArith
. The now public lemmas are mostly about compatibility of multiplication and power with relational operators and simple convenience lemmas e.g. for reduction ofQ
values. The following moved lemmas have been renamed:Q_factorDenom
toQmult_frac_l
,Q_reduce_fl
toQreduce_num_l
,Qle_neq
toQlt_leneq
,Qmult_lt_le_compat_nonneg
toQmult_le_lt_compat_pos
,Qpower_pos_lt
toQpower_0_lt
,Qpower_lt_1_increasing
toQpower_1_lt_pos
,Qpower_lt_1_increasing'
toQpower_1_lt
,Qpower_le_1_increasing
toQpower_1_le_pos
,Qpower_le_1_increasing'
toQpower_1_le
,Qzero_eq
toQreduce_zero
,Qpower_lt_compat
toQpower_lt_compat_l
,Qpower_le_compat
toQpower_le_compat_l
,Qpower_lt_compat_inv
toQpower_lt_compat_l_inv
,Qpower_le_compat_inv
toQpower_le_compat_l_inv
,Qpower_decomp'
toQpower_decomp_pos
andQarchimedeanExp2_Pos
toQarchimedean_power2_pos
. The following lemmas have been renamed and the sides of the equality swapped:Qinv_swap_pos
toQinv_pos
,Qinv_swap_neg
toQinv_neg
and. The following lemmas have been deleted:Q_factorNum_l
andQ_factorNum
. The lemmaQopp_lt_compat
has been moved fromtheories/QArith/Qround.v
totheories/QArith/QArith_base.v
. About 10 additional lemmas have been added for similar cases as the moved lemmas. Compatibility notations are not provided because QExtra is considered internal (excluded from the library documentation) (#14293, by Michael Soegtrop).Changed: Importing
ZArith
no longer has the side-effect of closingZ_scope
(#14343, fixes #13307, by Ralf Jung).Removed:
IF_then_else
definition and correspondingIF P then Q else R
notation (#13871, by Yishuai Li).Removed: from
List.v
deprecated/unexpected dependenciesSetoid
,Le
,Gt
,Minus
,Lt
(#13986, by Andrej Dudenhefner).Deprecated: Unsigned primitive integers are now named
uint63
instead ofint63
. TheInt63
module is replaced byUint63
. The full list of changes is described in the PR (#13895, by Ana Borges).Added:
leb
andltb
functions forascii
(#13080, by Yishuai Li).Added: Library for signed primitive integers, Sint63. The following operations were added to the kernel: division, remainder, comparison functions, and arithmetic shift right. Everything else works the same for signed and unsigned ints (#13559, fixes #12109, by Ana Borges, Guillaume Melquiond and Pierre Roux).
Added: Lemmas about vectors related with
to_list
:length_to_list
,of_list_to_list_opp
,to_list_nil
,to_list_cons
,to_list_hd
,to_list_last
,to_list_const
,to_list_nth_order
,to_list_tl
,to_list_append
,to_list_rev_append_tail
,to_list_rev_append
,to_list_rev
,to_list_map
,to_list_fold_left
,to_list_fold_right
,to_list_Forall
,to_list_Exists
,to_list_In
,to_list_Forall2
(#13671, by Olivier Laurent).Added: Lemmas about
count_occ
:count_occ_app
,count_occ_elt_eq
,count_occ_elt_neq
,count_occ_bound
,count_occ_repeat_eq
,count_occ_repeat_neq
,count_occ_unique
,count_occ_repeat_excl
,count_occ_sgt
,Permutation_count_occ
(#13804, by Olivier Laurent with help of Jean-Christophe Léchenet).Added: Lemmas to
List
:Exists_map
,Exists_concat
,Exists_flat_map
,Forall_map
,Forall_concat
,Forall_flat_map
,nth_error_map
,nth_repeat
,nth_error_repeat
(#13955, by Andrej Dudenhefner, with help from Olivier Laurent).Added:
Cantor.v
containing the Cantor pairing function and its inverse.Cantor.to_nat : nat * nat -> nat
andCantor.of_nat : nat -> nat * nat
are the respective bijections betweennat * nat
andnat
(#14008, by Andrej Dudenhefner).Added: Lemmas to
Q
:Qeq_from_parts
,Qden_cancel
,Qnum_cancel
,Qreduce_l
,Qreduce_r
,Qmult_inject_Z_l
,Qmult_inject_Z_r
QArith_base Reduction of rationals; establishing equality for Qden/Qnum separately (#14087, by Karolin Varner).Added:
Coq.Structures.OrdersEx.String_as_OT
andCoq.Structures.OrdersEx.Ascii_as_OT
to make strings and ascii ordered types (using lexical order). (#14096, by Jason Gross).Added: Lemmas
app_eq_app
,Forall_nil_iff
,Forall_cons_iff
toList.v
(#14153, closes #1803, by Andrej Dudenhefner, with help from Olivier Laurent).Added:
Z
,positive
andN
constants can now be printed in hexadecimal by openinghex_Z_scope
,hex_positive_scope
, andhex_N_scope
respectively (#14263, by Jason Gross).Added: Absolute value function for Sint63 (#14384, by Ana Borges).
Added: Lemmas showing
firstn
andskipn
commute withmap
(#14406, by Rudy Peterson).Fixed: Haskell extraction is now compatible with GHC versions >= 9.0. Some
#if
statements have been added to extractunsafeCoerce
to its new location in newer versions of GHC. (#14345, fixes #14256, by Jason Gross).
Infrastructure and dependencies¶
Changed: Coq's configure script now requires absolute paths for the
-prefix
option (#12567, by Emilio Jesus Gallego Arias).Changed: The regular Coq package has been split in two: coq-core, with OCaml-based libraries and tools; and coq-stdlib, which contains the Gallina-based standard library. The package Coq now depends on both for compatiblity (#12567, by Emilio Jesus Gallego Arias, review by Vincent Laporte, Guillaume Melquiond, Enrico Tassi, and Théo Zimmerman).
Changed: Coq's OCaml parts and tools [
coq-core
] are now built using Dune. The main user-facing change is that Dune >= 2.5 is now required to build Coq. This was a large and complex change. If you are packager you may find some minor differences if you were using a lot of custom optimizations. Note that, in particular, the configure option-datadir
is not customizable anymore, and-bindir
has been removed in favor of$prefix/bin
. Moreover, the install procedure will ignore-docdir
and-etcdir
, unless you patch the makefile and use Dune >= 2.9. We usually recommended using a recent Dune version, if possible. For developers and plugin authors, see the entry indev/doc/changes.md
. For packagers and users, seedev/doc/INSTALL.make.md
(#13617, by Emilio Jesús Gallego Arias, Rudi Grinberg, and Théo Zimmerman; review and testing by Gaëtan Gilbert, Guillaume Melquiond, and Enrico Tassi)Changed: Undocumented variables
OLDROOT
andCOQPREFIXINSTALL
which added a prefix path tomake install
have been removed. Now,make install
does support the more standardDESTDIR
variable, akin to whatcoq_makefile
does (#14258, by Emilio Jesus Gallego Arias).Added: Support OCaml 4.12 (#13885, by Emilio Jesus Gallego Arias, review by Gaëtan Gilbert and Théo Zimmerman).
Miscellaneous¶
Changed: The representation of micromega caches was slightly altered for efficiency purposes. As a consequence all stale caches must be cleaned up (#13405, by Pierre-Marie Pédrot).
Fixed: Fix the timeout facility on Unix to allow for nested timeouts. Previous behavior on nested timeouts was that an "inner" timeout would replace an "outer" timeout, so that the outer timeout would no longer fire. With the new behavior, Unix and Windows implementations should be (approximately) equivalent (#13586, by Lasse Blaauwbroek).
Changes in 8.14.1¶
Kernel¶
Specification language, type inference¶
Fixed: Missing registration of universe constraints in
Module Type
elaboration (#14666, fixes #14505, by Hugo Herbelin).
Tactics¶
Commands and options¶
Fixed: anomaly with
Extraction Conservative Types
when extracting pattern-matching on singleton types (#14669, fixes #3527, by Hugo Herbelin).Fixed: a regular error instead of an anomaly when calling
Separate Extraction
in a module (#14670, fixes #10796, by Hugo Herbelin).
Version 8.13¶
Summary of changes¶
Coq version 8.13 integrates many usability improvements, as well as extensions of the core language. The main changes include:
Introduction of primitive persistent arrays in the core language, implemented using imperative persistent arrays.
Introduction of definitional proof irrelevance for the equality type defined in the SProp sort.
Cumulative record and inductive type declarations can now specify the variance of their universes.
Various bugfixes and uniformization of behavior with respect to the use of implicit arguments and the handling of existential variables in declarations, unification and tactics.
New warning for unused variables in catch-all match branches that match multiple distinct patterns.
New warning for
Hint
commands outside sections without a locality attribute, whose goal is to eventually remove the fragile default behavior of importing hints only when usingRequire
. The recommended fix is to declare hints asexport
, instead of the current defaultglobal
, meaning that they are imported throughRequire Import
only, notRequire
. See the following rationale and guidelines for details.General support for boolean attributes.
Many improvements to the handling of notations, including number notations, recursive notations and notations with bindings. A new algorithm chooses the most precise notation available to print an expression, which might introduce changes in printing behavior.
Tactic improvements in
lia
and itszify
preprocessing step, now supporting reasoning on boolean operators such asZ.leb
and supporting primitive integersInt63
.Typing flags can now be specified per-constant / inductive.
Improvements to the reference manual including updated syntax descriptions that match Coq's grammar in several chapters, and splitting parts of the tactics chapter to independent sections.
See the Changes in 8.13+beta1 section and following sections for the detailed list of changes, including potentially breaking changes marked with Changed.
Coq's documentation is available at https://coq.github.io/doc/v8.13/refman (reference manual), and https://coq.github.io/doc/v8.13/stdlib (documentation of the standard library). Developer documentation of the ML API is available at https://coq.github.io/doc/v8.13/api.
Maxime Dénès, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Michael Soegtrop and Théo Zimmermann worked on maintaining and improving the continuous integration system and package building infrastructure.
Erik Martin-Dorel has maintained the Coq Docker images that are used in many Coq projects for continuous integration.
The opam repository for Coq packages has been maintained by Guillaume Claret, Karl Palmskog, Matthieu Sozeau and Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
Our current 32 maintainers are Yves Bertot, Frédéric Besson, Tej Chajed, Cyril Cohen, Pierre Corbineau, Pierre Courtieu, Maxime Dénès, Jim Fehrle, Julien Forest, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Georges Gonthier, Benjamin Grégoire, Jason Gross, Hugo Herbelin, Vincent Laporte, Olivier Laurent, Assia Mahboubi, Kenji Maillard, Guillaume Melquiond, Pierre-Marie Pédrot, Clément Pit-Claudel, Kazuhiko Sakaguchi, Vincent Semeria, Michael Soegtrop, Arnaud Spiwack, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Anton Trunov, Li-yao Xia and Théo Zimmermann.
The 51 contributors to this version are Reynald Affeldt, Tanaka Akira, Frédéric Besson, Lasse Blaauwbroek, Clément Blaudeau, Martin Bodin, Ali Caglayan, Tej Chajed, Cyril Cohen, Julien Coolen, Matthew Dempsky, Maxime Dénès, Andres Erbsen, Jim Fehrle, Emilio Jesús Gallego Arias, Attila Gáspár, Paolo G. Giarrusso, Gaëtan Gilbert, Jason Gross, Benjamin Grégoire, Hugo Herbelin, Wolf Honore, Jasper Hugunin, Ignat Insarov, Ralf Jung, Fabian Kunze, Vincent Laporte, Olivier Laurent, Larry D. Lee Jr, Thomas Letan, Yishuai Li, James Lottes, Jean-Christophe Léchenet, Kenji Maillard, Erik Martin-Dorel, Yusuke Matsushita, Guillaume Melquiond, Carl Patenaude-Poulin, Clément Pit-Claudel, Pierre-Marie Pédrot, Pierre Roux, Kazuhiko Sakaguchi, Vincent Semeria, Michael Soegtrop, Matthieu Sozeau, Enrico Tassi, Anton Trunov, Edward Wang, Li-yao Xia, Beta Ziliani and Théo Zimmermann.
The Coq community at large helped improve the design of this new version via the GitHub issue and pull request system, the Coq development mailing list coqdev@inria.fr, the coq-club@inria.fr mailing list, the Discourse forum and the Coq Zulip chat.
Version 8.13's development spanned 5 months from the release of Coq 8.12.0. Enrico Tassi and Maxime Dénès are the release managers of Coq 8.13. This release is the result of 400 merged PRs, closing ~100 issues.
Changes in 8.13+beta1¶
Kernel¶
Added: Definitional UIP, only when
Definitional UIP
is enabled. This models definitional uniqueness of identity proofs for the equality type in SProp. It is deactivated by default as it can lead to non-termination in combination with impredicativity. Use of this flag is also printed byPrint Assumptions
. See documentation of the flag for details (#10390, by Gaëtan Gilbert).Added: Built-in support for persistent arrays, which expose a functional interface but are implemented using an imperative data structure, for better performance (#11604, by Maxime Dénès and Benjamin Grégoire, with help from Gaëtan Gilbert).
Primitive arrays are irrelevant in their single polymorphic universe (same as a polymorphic cumulative list inductive would be) (#13356, fixes #13354, by Gaëtan Gilbert).
Fixed: A loss of definitional equality for declarations obtained through
Include
when entering the scope of aModule
orModule Type
was causingSearch
not to see the included declarations (#12537, fixes #12525 and #12647, by Hugo Herbelin).Fixed: Fix an incompleteness in the typechecking of
match
for cumulative inductive types. This could result in breaking subject reduction (#13501, fixes #13495, by Matthieu Sozeau).
Specification language, type inference¶
Changed: Boolean attributes are now specified using key/value pairs, that is to say
identattr= yesno?
. If the value is missing, the default isyes
. The old syntax is still supported, but produces thedeprecated-attribute-syntax
warning.Deprecated attributes are
universes(monomorphic)
,universes(notemplate)
anduniverses(noncumulative)
, which are respectively replaced byuniverses(polymorphic=no)
,universes(template=no)
anduniverses(cumulative=no)
. Attributesprogram
andcanonical
are also affected, with the syntaxidentattr(false)
being deprecated in favor ofidentattr=no
(#13312, by Emilio Jesus Gallego Arias).Changed: Heuristics for universe minimization to
Set
: also use constraintsProp <= i
(#10331, by Gaëtan Gilbert with help from Maxime Dénès and Matthieu Sozeau, fixes #12414).Changed: The type given to
Instance
is no longer automatically generalized over unbound and generalizable variables. UseInstance : `{type}
instead ofInstance : type
to get the old behavior, or enable the compatibility flagInstance Generalized Output
(#13188, fixes #6042, by Gaëtan Gilbert).Changed: Tweaked the algorithm giving default names to arguments. Should reduce the frequency that argument names get an unexpected suffix. Also makes
Mangle Names
not mess up argument names (#12756, fixes #12001 and #6785, by Jasper Hugunin).Removed: Undocumented and experimental forward class hint feature
:>>
. Use:>
(seeof_type
) instead (#13106, by Pierre-Marie Pédrot).Added: Commands
Inductive
,Record
and synonyms now support syntaxInductive foo@{=i +j *k l}
to specify variance information for their universes (in Cumulative mode) (#12653, by Gaëtan Gilbert).Added: Warning on unused variables in pattern-matching branches of
match
serving as catch-all branches for at least two distinct patterns (#12768, fixes #12762, by Hugo Herbelin).Added: Definition and (Co)Fixpoint now support the
using
attribute. It has the same effect asProof using
, which is only available in interactive mode (#13183, by Enrico Tassi).Added: Typing flags can now be specified per-constant / inductive, this allows to fine-grain specify them from plugins or attributes. See Controlling Typing Flags for details on attribute syntax (#12586, by Emilio Jesus Gallego Arias).
Added: Inference of return predicate of a
match
by inversion takes sort elimination constraints into account (#13290, grants #13278, by Hugo Herbelin).Fixed: Implicit arguments taken into account in defined fields of a record type declaration (#13166, fixes #13165, by Hugo Herbelin).
Fixed: Allow use of typeclass inference for the return predicate of a
match
(was deactivated in versions 8.10 to 8.12, #13217, fixes #13216, by Hugo Herbelin).Fixed: A case of unification raising an anomaly IllTypedInstance (#13376, fixes #13266, by Hugo Herbelin).
Fixed: Using
{wf ...}
in local fixpoints is an error, not an anomaly (#13383, fixes #11816, by Hugo Herbelin).Fixed: Issue when two expressions involving different projections and one is primitive need to be unified (#13386, fixes #9971, by Hugo Herbelin).
Fixed: A bug producing ill-typed instances of existential variables when let-ins interleaved with assumptions (#13387, fixes #12348, by Hugo Herbelin).
Notations¶
Changed: In notations (except in custom entries), the misleading
syntax_modifier
ident ident
(which accepted either an identifier or a_
) is deprecated and should be replaced byident name
. If the intent was really to only parse identifiers, this will eventually become possible, but only as of Coq 8.15. In custom entries, the meaning ofident ident
is silently changed from parsing identifiers or_
to parsing only identifiers without warning, but this presumably affects only rare, recent and relatively experimental code (#11841, fixes #9514, by Hugo Herbelin).Changed: Improved support for notations/abbreviations with mixed terms and patterns (such as the forcing modality) (#12099, by Hugo Herbelin).
Changed Rational and real constants are parsed differently. The exponent is now encoded separately from the fractional part using
Z.pow_pos
. This way, parsing large exponents can no longer blow up and constants are printed in a form closer to the one in which they were parsed (i.e.,102e-2
is reprinted as such and not1.02
) (#12218, by Pierre Roux).Changed: Scope information is propagated in indirect applications to a reference prefixed with
@
; this covers for instance the caser.(@p) t
where scope information fromp
is now taken into account for interpretingt
(#12685, by Hugo Herbelin).Changed: New model for
only parsing
andonly printing
notations with support for at most one parsing-and-printing or only-parsing notation per notation and scope, but an arbitrary number of only-printing notations (#12950, fixes #4738 and #9682 and part 2 of #12908, by Hugo Herbelin).Changed: Redeclaring a notation also reactivates its printing rule; in particular a second
Import
of the same module reactivates the printing rules declared in this module. In theory, this leads to changes in behavior for printing. However, this is mitigated in general by the adoption in #12986 of a priority given to notations which match a larger part of the term to print (#12984, fixes #7443 and #10824, by Hugo Herbelin).Changed: Use of notations for printing now gives preference to notations which match a larger part of the term to abbreviate (#12986, by Hugo Herbelin).
Removed OCaml parser and printer for real constants have been removed. Real constants are now handled with proven Coq code (#12218, by Pierre Roux).
Deprecated
Numeral.v
is deprecated, please useNumber.v
instead (#12218, by Pierre Roux).Deprecated:
Numeral Notation
, please useNumber Notation
instead (#12979, by Pierre Roux).Added:
Printing Float
flag to print primitive floats as hexadecimal instead of decimal values. This is included in thePrinting All
flag (#11986, by Pierre Roux).Added: Number Notation and String Notation commands now support parameterized inductive and non-inductive types (#12218, fixes #12035, by Pierre Roux, review by Jason Gross and Jim Fehrle for the reference manual).
Added: Added support for encoding notations of the form
x ⪯ y ⪯ .. ⪯ z ⪯ t
. This feature is considered experimental (#12765, by Hugo Herbelin).Added: The
binder
entry ofNotation
can now be used in notations expecting a single (non-recursive) binder (#13265, by Hugo Herbelin, see section Notations and binders of the reference manual).Fixed: Issues in the presence of notations recursively referring to another applicative notations, such as missing scope propagation, or failure to use a notation for printing (#12960, fixes #9403 and #10803, by Hugo Herbelin).
Fixed: Capture the names of global references by binders in the presence of notations for binders (#12965, fixes #9569, by Hugo Herbelin).
Fixed: Preventing notations for constructors to involve binders (#13092, fixes #13078, by Hugo Herbelin).
Fixed: Notations understand universe names without getting confused by different imported modules between declaration and use locations (#13415, fixes #13303, by Gaëtan Gilbert).
Tactics¶
Changed: In
refine
, new existential variables unified with existing ones are no longer considered as fresh. The behavior ofsimple refine
no longer depends on the orientation of evar-evar unification problems, and new existential variables are always turned into (unshelved) goals. This can break compatibility in some cases (#7825, by Matthieu Sozeau, with help from Maxime Dénès, review by Pierre-Marie Pédrot and Enrico Tassi, fixes #4095 and #4413).Changed: Giving an empty list of occurrences after
in
in tactics is no longer permitted. Omitting thein
gives the same behavior (#13237, fixes #13235, by Hugo Herbelin).Removed:
at occs_nums
clauses in tactics such asunfold
no longer allow negative values. A "-" before the list (for set complement) is still supported. Ex: "at -1 -2" is no longer supported but "at -1 2" is (#13403, by Jim Fehrle).Removed: A number of tactics that formerly accepted negative numbers as parameters now give syntax errors for negative values. These include {e}constructor, do, timeout, 9 {e}auto tactics and psatz* (#13417, by Jim Fehrle).
Removed: The deprecated and undocumented
prolog
tactic was removed (#12399, by Pierre-Marie Pédrot).Removed:
info
tactic that was deprecated in 8.5 (#12423, by Jim Fehrle).Deprecated: Undocumented
eauto nat_or_var nat_or_var
syntax in favor of newbfs eauto
. Also deprecated 2-integer syntax fordebug eauto
andinfo_eauto
(Usebfs eauto
with theInfo Eauto
orDebug Eauto
flags instead.) (#13381, by Jim Fehrle).Added:
lia
is extended to deal with boolean operators e.g.andb
orZ.leb
(aslia
gets more powerful, this may break proof scripts relying onlia
failure, #11906, by Frédéric Besson).Added:
apply … in
supports several hypotheses (#12246, by Hugo Herbelin; grants #9816).Added: The
zify
tactic can now be extended by redefining thezify_pre_hook
tactic. (#12552, by Kazuhiko Sakaguchi).Added: The
zify
tactic provides support for primitive integers (moduleZifyInt63
) (#12648, by Frédéric Besson).Fixed: Avoid exposing an internal name of the form
_tmp
when applying the_
introduction pattern which would break a dependency (#13337, fixes #13336, by Hugo Herbelin).Fixed: The case of tactics, such as
eapply
, producing existential variables under binders with an ill-formed instance (#13373, fixes #13363, by Hugo Herbelin).
Tactic language¶
SSReflect¶
Commands and options¶
Changed: Drop prefixes from grammar non-terminal names, e.g. "constr:global" -> "global", "Prim.name" -> "name". Visible in the output of
Print Grammar
andPrint Custom Grammar
(#13096, by Jim Fehrle).Changed: When declaring arbitrary terms as hints, unsolved evars are not abstracted implicitly anymore and instead raise an error (#13139, by Pierre-Marie Pédrot).
Removed: In the
Extraction Language
command, removeOcaml
as a valid value. UseOCaml
instead. This was deprecated in Coq 8.8, #6261 (#13016, by Jim Fehrle).Deprecated: Hint locality currently defaults to
local
in a section andglobal
otherwise, but this will change in a future release. Hints added outside of sections without an explicit locality now generate a deprecation warning. We recommend usingexport
where possible (#13384, by Pierre-Marie Pédrot).Deprecated:
Grab Existential Variables
andExistential
commands (#12516, by Maxime Dénès).Added: The
export
locality can now be used for all Hint commands, includingHint Cut
,Hint Mode
,Hint Transparent
/Opaque
andRemove Hints
(#13388, by Pierre-Marie Pédrot).Added: Support for automatic insertion of coercions in
Search
patterns. Additionally, head patterns are now automatically interpreted as types (#13255, fixes #13244, by Hugo Herbelin).Added: The
Proof using
command can now be used without loading the Ltac plugin (-noinit
mode) (#13339, by Théo Zimmermann).Added: Clarify in the documentation that
Add ML Path
is not exported to compiled files (#13345, fixes #13344, by Hugo Herbelin).
Tools¶
Changed: Option
-native-compiler
of the configure script now impacts the default value of the-native-compiler
option of coqc. The-native-compiler
option of the configure script supports a newondemand
value, which becomes the default, thus preserving the previous default behavior. The stdlib is still precompiled when configuring with-native-compiler yes
. It is not precompiled otherwise. This an implementation of point 2 of CEP #48 (#13352, by Pierre Roux).Changed: Added the ability for coq_makefile to directly set the installation folders, through the
COQLIBINSTALL
andCOQDOCINSTALL
variables. See CoqMakefile.local (#12389, by Martin Bodin, review of Enrico Tassi).Removed: The option
-I
of coqchk was removed (it was deprecated in Coq 8.8) (#12613, by Gaëtan Gilbert).Fixed:
coqchk
no longer reports names from inner modules of opaque modules as axioms (#12862, fixes #12845, by Jason Gross).
CoqIDE¶
Added: Support showing diffs for
Show Proof
in CoqIDE from theView
menu. See "Show Proof" differences (#12874, by Jim Fehrle and Enrico Tassi)Added: Support for flag
Printing Goal Names
in View menu (#13145, by Hugo Herbelin).
Standard library¶
Changed: In the reals theory changed the epsilon in the definition of the modulus of convergence for CReal from 1/n (n in positive) to 2^z (z in Z) so that a precision coarser than one is possible. Also added an upper bound to CReal to enable more efficient computations (#12186, by Michael Soegtrop).
Changed: Int63 notations now match up with the rest of the standard library:
a \% m
,m == n
,m < n
,m <= n
, andm ≤ n
have been replaced witha mod m
,m =? n
,m <? n
,m <=? n
, andm ≤? n
. The old notations are still available as deprecated notations. Additionally, there is now aCoq.Numbers.Cyclic.Int63.Int63.Int63Notations
module that users can import to get theInt63
notations without unqualifying the various primitives (#12479, fixes #12454, by Jason Gross).Changed: PrimFloat notations now match up with the rest of the standard library:
m == n
,m < n
, andm <= n
have been replaced withm =? n
,m <? n
, andm <=? n
. The old notations are still available as deprecated notations. Additionally, there is now aCoq.Floats.PrimFloat.PrimFloatNotations
module that users can import to get thePrimFloat
notations without unqualifying the various primitives (#12556, fixes #12454, by Jason Gross).Changed: the sort of cyclic numbers from Type to Set. For backward compatibility, a dynamic sort was defined in the 3 packages bignums, coqprime and color. See for example commit 6f62bda in bignums (#12801, by Vincent Semeria).
Changed:
Require Import Coq.nsatz.NsatzTactic
now allows usingnsatz
withZ
andQ
without having to supply instances or usingRequire Import Coq.nsatz.Nsatz
, which transitively requires unneeded files declaring axioms used in the reals (#12861, fixes #12860, by Jason Gross).Deprecated:
prod_curry
andprod_uncurry
, in favor ofuncurry
andcurry
(#12716, by Yishuai Li).Added: New lemmas about
repeat
inList
andPermutation
:repeat_app
,repeat_eq_app
,repeat_eq_cons
,repeat_eq_elt
,Forall_eq_repeat
,Permutation_repeat
(#12799, by Olivier Laurent).Added: Extend some list lemmas to both directions:
app_inj_tail_iff
,app_inv_head_iff
,app_inv_tail_iff
(#12094, fixes #12093, by Edward Wang).Added:
Decidable
instance for negation (#12420, by Yishuai Li).Fixed:
Coq.Program.Wf.Fix_F_inv
andCoq.Program.Wf.Fix_eq
are now axiom-free, and no longer assuming proof irrelevance (#13365, by Li-yao Xia).
Infrastructure and dependencies¶
Changed: When compiled with OCaml >= 4.10.0, Coq will use the new best-fit GC policy, which should provide some performance benefits. Coq's policy is optimized for speed, but could increase memory consumption in some cases. You are welcome to tune it using the
OCAMLRUNPARAM
variable and report back on good settings so we can improve the defaults (#13040, fixes #11277, by Emilio Jesus Gallego Arias).Changed: Coq now uses the zarith library, based on GNU's gmp instead of
num
which is deprecated upstream. The custombigint
module is no longer provided (#11742, #13007, by Emilio Jesus Gallego Arias and Vicent Laporte, with help from Frédéric Besson).
Changes in 8.13.0¶
Commands and options¶
Changed: The warning
custom-entry-overriden
has been renamed tocustom-entry-overridden
(with two d's) (#13556, by Simon Friis Vindum).
Changes in 8.13.1¶
Kernel¶
Fixed: Fix arities of VM opcodes for some floating-point operations that could cause memory corruption (#13867, by Guillaume Melquiond).
CoqIDE¶
Added: Option
-v
and--version
to CoqIDE (#13870, by Guillaume Melquiond).
Changes in 8.13.2¶
Kernel¶
Fixed: Crash when using
vm_compute
on an irreduciblePArray.set
(#14005, fixes #13998, by Guillaume Melquiond).Fixed: Never store persistent arrays as VM / native structured values. This could be used to make vo marshalling crash, and probably breaking some other invariants of the kernel (#14007, fixes #14006, by Pierre-Marie Pédrot).
Tactic language¶
Version 8.12¶
Summary of changes¶
Coq version 8.12 integrates many usability improvements, in particular with respect to notations, scopes and implicit arguments, along with many bug fixes and major improvements to the reference manual. The main changes include:
New binder notation for non-maximal implicit arguments using
[ ]
allowing to set and see the implicit status of arguments immediately.New notation
Inductive I A | x : s := ...
to distinguish the uniform from the non-uniform parameters in inductive definitions.More robust and expressive treatment of implicit inductive parameters in inductive declarations.
Improvements in the treatment of implicit arguments and partially applied constants in notations, parsing of hexadecimal number notation and better handling of scopes and coercions for printing.
A correct and efficient coercion coherence checking algorithm, avoiding spurious or duplicate warnings.
An improved
Search
command which accepts complex queries. Note that this takes precedence over the now deprecated ssreflect search.Many additions and improvements of the standard library.
Improvements to the reference manual include a more logical organization of chapters along with updated syntax descriptions that match Coq's grammar in most but not all chapters.
Additionally, the omega
tactic is deprecated in this version of Coq,
and we recommend users to switch to lia
in new proof scripts.
See the Changes in 8.12+beta1 section and following sections for the detailed list of changes, including potentially breaking changes marked with Changed.
Coq's documentation is available at https://coq.github.io/doc/v8.12/refman (reference manual), and https://coq.github.io/doc/v8.12/stdlib (documentation of the standard library). Developer documentation of the ML API is available at https://coq.github.io/doc/v8.12/api.
Maxime Dénès, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Michael Soegtrop and Théo Zimmermann worked on maintaining and improving the continuous integration system and package building infrastructure.
Erik Martin-Dorel has maintained the Coq Docker images that are used in many Coq projects for continuous integration.
The opam repository for Coq packages has been maintained by Guillaume Claret, Karl Palmskog, Matthieu Sozeau and Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
Previously, most components of Coq had a single principal maintainer. This was changed in 8.12 (#11295) so that every component now has a team of maintainers, who are in charge of reviewing and merging incoming pull requests. This gave us a chance to significantly expand the pool of maintainters and provide faster feedback to contributors. Special thanks to all our maintainers!
Our current 31 maintainers are Yves Bertot, Frédéric Besson, Tej Chajed, Cyril Cohen, Pierre Corbineau, Pierre Courtieu, Maxime Dénès, Jim Fehrle, Julien Forest, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Georges Gonthier, Benjamin Grégoire, Jason Gross, Hugo Herbelin, Vincent Laporte, Assia Mahboubi, Kenji Maillard, Guillaume Melquiond, Pierre-Marie Pédrot, Clément Pit-Claudel, Kazuhiko Sakaguchi, Vincent Semeria, Michael Soegtrop, Arnaud Spiwack, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Anton Trunov, Li-yao Xia, Théo Zimmermann
The 59 contributors to this version are Abhishek Anand, Yves Bertot, Frédéric Besson, Lasse Blaauwbroek, Simon Boulier, Quentin Carbonneaux, Tej Chajed, Arthur Charguéraud, Cyril Cohen, Pierre Courtieu, Matthew Dempsky, Maxime Dénès, Andres Erbsen, Erika (@rrika), Nikita Eshkeev, Jim Fehrle, @formalize, Emilio Jesús Gallego Arias, Paolo G. Giarrusso, Gaëtan Gilbert, Jason Gross, Samuel Gruetter, Attila Gáspár, Hugo Herbelin, Jan-Oliver Kaiser, Robbert Krebbers, Vincent Laporte, Olivier Laurent, Xavier Leroy, Thomas Letan, Yishuai Li, Kenji Maillard, Erik Martin-Dorel, Guillaume Melquiond, Ike Mulder, Guillaume Munch-Maccagnoni, Antonio Nikishaev, Karl Palmskog, Pierre-Marie Pédrot, Clément Pit-Claudel, Ramkumar Ramachandra, Lars Rasmusson, Daniel de Rauglaudre, Talia Ringer, Pierre Roux, Kazuhiko Sakaguchi, Vincent Semeria, @scinart, Kartik Singhal, Michael Soegtrop, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Ralf Treinen, Anton Trunov, Bernhard M. Wiedemann, Li-yao Xia, Nickolai Zeldovich and Théo Zimmermann.
Many power users helped to improve the design of this new version via the GitHub issue and pull request system, the Coq development mailing list coqdev@inria.fr, the coq-club@inria.fr mailing list, the Discourse forum and the new Coq Zulip chat (thanks to Cyril Cohen for organizing the move from Gitter).
Version 8.12's development spanned 6 months from the release of Coq 8.11.0. Emilio Jesus Gallego Arias and Théo Zimmermann are the release managers of Coq 8.12. This release is the result of ~500 PRs merged, closing ~100 issues.
Changes in 8.12+beta1¶
Kernel¶
Specification language, type inference¶
Changed: The deprecation warning raised since Coq 8.10 when a trailing implicit is declared to be non-maximally inserted (with the command
Arguments
) has been turned into an error (#11368, by SimonBoulier).Changed: Typeclass resolution, accessible through
typeclasses eauto
, now suspends constraints according to their modes instead of failing. If a typeclass constraint does not match any of the declared modes for its class, the constraint is postponed, and the proof search continues on other goals. Proof search does a fixed point computation to try to solve them at a later stage of resolution. It does not fail if there remain only stuck constraints at the end of resolution. This makes typeclasses with declared modes more robust with respect to the order of resolution (#10858, fixes #9058, by Matthieu Sozeau).Added: Warn when manual implicit arguments are used in unexpected positions of a term (e.g. in
Check id (forall {x}, x)
) or when an implicit argument name is shadowed (e.g. inCheck fun f : forall {x:nat} {x}, nat => f
) (#10202, by Hugo Herbelin).Added:
Arguments
now supports setting implicit an anonymous argument, as e.g. inArguments id {A} {_}
(#11098, by Hugo Herbelin, fixes #4696, #5173, #9098).Added: Syntax for non-maximal implicit arguments in definitions and terms using square brackets. The syntax is
[x : A]
,[x]
,`[A]
to be consistent with the commandArguments
(#11235, by Simon Boulier).Added:
Implicit Types
are now taken into account for printing. To inhibit it, unset thePrinting Use Implicit Types
flag (#11261, by Hugo Herbelin, granting #10366).Added: New syntax
Inductive
ident binder* | binder* := ...
to specify which parameters of an inductive type are uniform. See Parameterized inductive types (#11600, by Gaëtan Gilbert).Added: Warn when using
Fixpoint
orCoFixpoint
for definitions which are not recursive (#12121, by Hugo Herbelin).Fixed: More robust and expressive treatment of implicit inductive parameters in inductive declarations (#11579, by Maxime Dénès, Gaëtan Gilbert and Jasper Hugunin; fixes #7253 and #11585).
Fixed: Anomaly which could be raised when printing binders with implicit types (#12323, by Hugo Herbelin; fixes #12322).
Fixed: Case of an anomaly in trying to infer the return clause of an ill-typed
match
(#12422, fixes #12418, by Hugo Herbelin).
Notations¶
Changed: Notation scopes are now always inherited in notations binding a partially applied constant, including for notations binding an expression of the form
@qualid
. The latter was not the case beforehand (part of #11120).Changed: The printing algorithm now interleaves search for notations and removal of coercions (#11172, by Hugo Herbelin).
Changed: Nicer printing for decimal constants in R and Q. 1.5 is now printed 1.5 rather than 15e-1 (#11848, by Pierre Roux).
Removed: deprecated
compat
modifier ofNotation
andInfix
commands. Use thedeprecated
attribute instead (#11113, by Théo Zimmermann, with help from Jason Gross).Deprecated: Numeral Notation on
Decimal.uint
,Decimal.int
andDecimal.decimal
are replaced respectively by numeral notations onNumeral.uint
,Numeral.int
andNumeral.numeral
(#11948, by Pierre Roux).Added: Notations declared with the
where
clause in the declaration of inductive types, coinductive types, record fields, fixpoints and cofixpoints now support theonly parsing
modifier (#11602, by Hugo Herbelin).Added:
Printing Parentheses
flag to print parentheses even when implied by associativity or precedence (#11650, by Hugo Herbelin and Abhishek Anand).Added: Numeral notations now parse hexadecimal constants such as
0x2a
or0xb.2ap-2
. Parsers added fornat
,positive
,Z
,N
,Q
,R
, primitive integers and primitive floats (#11948, by Pierre Roux).Added: Abbreviations support arguments occurring both in term and binder position (#8808, by Hugo Herbelin).
Fixed: Different interpretations in different scopes of the same notation string can now be associated with different printing formats (#10832, by Hugo Herbelin, fixes #6092 and #7766).
Fixed: Parsing and printing consistently handle inheritance of implicit arguments in notations. With the exception of notations of the form
Notation string := @qualid
andNotation ident := @qualid
which inhibit implicit arguments, all notations binding a partially applied constant, as e.g. inNotation string := (qualid arg+)
, orNotation string := (@qualid arg+)
, orNotation ident := (qualid arg+)
, orNotation ident := (@qualid arg+)
, inherit the remaining implicit arguments (#11120, by Hugo Herbelin, fixing #4690 and #11091).Fixed: Notations in
only printing
mode do not uselessly reserve parsing keywords (#11590, by Hugo Herbelin, fixes #9741).Fixed: Numeral Notations now play better with multiple scopes for the same inductive type. Previously, when multiple numeral notations were defined for the same inductive, only the last one was considered for printing. Now, among the notations that are usable for printing and either have a scope delimiter or are open, the selection is made according to the order of open scopes, or according to the last defined notation if no appropriate scope is open (#12163, fixes #12159, by Pierre Roux, review by Hugo Herbelin and Jason Gross).
Tactics¶
Changed: The
rapply
tactic inCoq.Program.Tactics
now handles arbitrary numbers of underscores and takes in auconstr
. In rare cases where users were relying onrapply
inserting exactly 15 underscores and no more, due to the lemma having a completely unspecified codomain (and thus allowing for any number of underscores), the tactic will now loop instead (#10760, by Jason Gross).Changed: The
auto with zarith
tactic and variations (includingintuition
) may now calllia
instead ofomega
(when theOmega
module is loaded); more goals may be automatically solved, fewer section variables will be captured spuriously (#11018, by Vincent Laporte).Changed: The new
NativeCompute Timing
flag causes calls tonative_compute
(as well as kernel calls to the native compiler) to emit separate timing information about conversion to native code, compilation, execution, and reification. It replaces the timing information previously emitted when the-debug
command-line flag was set, and allows more fine-grained timing of the native compiler (#11025, by Jason Gross). Additionally, the timing information now uses real time rather than user time (fixes #11962, #11963, by Jason Gross)Changed: Improve the efficiency of
PreOmega.elim_let
using an iterator implemented in OCaml (#11370, by Frédéric Besson).Changed: Improve the efficiency of
zify
by rewriting the remaining Ltac code in OCaml (#11429, by Frédéric Besson).Changed: Backtrace information for tactics has been improved (#11755, by Emilio Jesus Gallego Arias).
Changed: The default tactic used by
firstorder
isauto with core
instead ofauto with *
; see Solvers for logic and equality for details; old behavior can be reset by using the-compat 8.12
command-line flag; to ease the migration of legacy code, the default solver can be set todebug auto with *
withSet Firstorder Solver debug auto with *
(#11760, by Vincent Laporte).Changed:
autounfold
no longer fails when theOpaque
command is used on constants in the hint databases (#11883, by Attila Gáspár).Changed: Tactics with qualified name of the form
Coq.Init.Notations
are now qualified with prefixCoq.Init.Ltac
; users of the-noinit
option should now importCoq.Init.Ltac
if they want to use Ltac (#12023, by Hugo Herbelin; minor source of incompatibilities).Changed: Tactic
subst
ident
now fails over a section variable which is indirectly dependent in the goal; the incompatibility can generally be fixed by first clearing the hypotheses causing an indirect dependency, as reported by the error message, or by usingrewrite
... in *
instead; similarly,subst
has no more effect on such variables (#12146, by Hugo Herbelin; fixes #10812 and #12139).Changed: The check that
unfold
arguments were indeed unfoldable has been moved to runtime (#12256, by Pierre-Marie Pédrot; fixes #5764, #5159, #4925 and #11727).Changed When the tactic
functional induction
c1 c2 ... cn
is used with no parenthesis aroundc1 c2 ... cn
,c1 c2 ... cn
is now read as one single applicative term. In particular implicit arguments should be omitted. Rare source of incompatibility (#12326, by Pierre Courtieu).Changed: When using
exists
oreexists
with multiple arguments, the evaluation of arguments and applications of constructors are now interleaved. This improves unification in some cases (#12366, fixes #12365, by Attila Gáspár).Removed: Undocumented
omega with
. Usinglia
is the recommended replacement, although the old semantics ofomega with *
can also be recovered withzify; omega
(#11288, by Emilio Jesus Gallego Arias).Removed: Deprecated syntax
_eqn
fordestruct
andremember
. Useeqn:
syntax instead (#11877, by Hugo Herbelin).Removed:
at
clauses can no longer be used withautounfold
. Since they had no effect, it is safe to remove them (#11883, by Attila Gáspár).Deprecated: The
omega
tactic is deprecated; uselia
from the Micromega plugin instead (#11976, by Vincent Laporte).Added: The
zify
tactic is now aware ofPos.pred_double
,Pos.pred_N
,Pos.of_nat
,Pos.add_carry
,Pos.pow
,Pos.square
,Z.pow
,Z.double
,Z.pred_double
,Z.succ_double
,Z.square
,Z.div2
, andZ.quot2
. Injections for internal definitions in moduleZifyBool
(isZero
andisLeZero
) are also added to help users to declare newzify
class instances using Micromega tactics (#10998, by Kazuhiko Sakaguchi).Added:
Show Lia Profile
prints some statistics aboutlia
calls (#11474, by Frédéric Besson).Added: Syntax
pose proof
(ident:=term)
as an alternative topose proof
term as ident
, following the model ofpose
(ident:=term)
(#11522, by Hugo Herbelin).Added: New tactical
with_strategy
which behaves like the commandStrategy
, with effects local to the given tactic (#12129, by Jason Gross).Added: The
zify
tactic is now aware ofNat.le
,Nat.lt
andNat.eq
(#12213, by Frédéric Besson; fixes #12210).Fixed:
zify
now handlesZ.pow_pos
by default. In Coq 8.11, this was the case only when loading moduleZifyPow
because this triggered a regression oflia
. The regression is now fixed, and the module kept only for compatibility (#11362, fixes #11191, by Frédéric Besson).Fixed: Efficiency regression of
lia
(#11474, fixes #11436, by Frédéric Besson).Fixed: The behavior of
autounfold
no longer depends on the names of terms and modules (#11883, fixes #7812, by Attila Gáspár).Fixed: Wrong type error in tactic
functional induction
(#12326, by Pierre Courtieu, fixes #11761, reported by Lasse Blaauwbroek).
Tactic language¶
Changed: The "reference" tactic generic argument now accepts arbitrary variables of the goal context (#12254, by Pierre-Marie Pédrot).
Added: An array library for Ltac2 (as compatible as possible with OCaml standard library) (#10343, by Michael Soegtrop).
Added: The Ltac2 rebinding command
Ltac2 Set
has been extended with the ability to give a name to the old value so as to be able to reuse it inside the new one (#11503, by Pierre-Marie Pédrot).Added: Ltac2 notations for
enough
andeenough
(#11740, by Michael Soegtrop).Added: New Ltac2 function
Fresh.Free.of_goal
to return the list of names of declarations of the current goal; new Ltac2 functionFresh.in_goal
to return a variable fresh in the current goal (#11882, by Hugo Herbelin).Added: Ltac2 notations for reductions in terms:
eval red_expr in term
(#11981, by Michael Soegtrop).Fixed: The
Ltac Profiling
machinery now correctly handles backtracking into multi-success tactics. The call-counts of some tactics are unfortunately inflated by 1, as some tactics are implicitly implemented astac + fail
, which has two entry-points rather than one (fixes #12196, #12197, by Jason Gross).
SSReflect¶
Changed: The
Search (ssreflect)
command that used to be available when loading thessreflect
plugin has been moved to a separate plugin that needs to be loaded separately:ssrsearch
(part of #8855, fixes #12253, by Théo Zimmermann).Deprecated:
Search (ssreflect)
(available throughRequire ssrsearch.
) in favor of theheadconcl:
clause ofSearch
(part of #8855, by Théo Zimmermann).
Flags, options and attributes¶
Changed: Legacy attributes can now be passed in any order (#11665, by Théo Zimmermann).
Removed:
Typeclasses Axioms Are Instances
flag, deprecated since 8.10. UseDeclare Instance
for axioms which should be instances (#11185, by Théo Zimmermann).Removed: Deprecated unsound compatibility
Template Check
flag that was introduced in 8.10 to help users gradually move their template polymorphic inductive type definitions outside sections (#11546, by Pierre-Marie Pédrot).Removed: Deprecated
Shrink Obligations
flag (#11828, by Emilio Jesus Gallego Arias).Removed: Unqualified
polymorphic
,monomorphic
,template
,notemplate
attributes (they were deprecated since Coq 8.10). Useuniverses(polymorphic)
,universes(monomorphic)
,universes(template)
anduniverses(notemplate)
instead (#11663, by Théo Zimmermann).Deprecated:
Hide Obligations
flag (#11828, by Emilio Jesus Gallego Arias).Added: Handle the
local
attribute inCanonical Structure
declarations (#11162, by Enrico Tassi).Added: New attributes supported when defining an inductive type
universes(cumulative)
,universes(noncumulative)
andprivate(matching)
, which correspond to legacy attributesCumulative
,NonCumulative
, and the previously undocumentedPrivate
(#11665, by Théo Zimmermann).Added: The Hint commands now accept the
export
locality as an attribute, allowing to make import-scoped hints (#11812, by Pierre-Marie Pédrot).Added:
Cumulative StrictProp
to control cumulativity of \(\SProp\) (#12034, by Gaëtan Gilbert).
Commands¶
Changed: The
Coercion
command has been improved to check the coherence of the inheritance graph. It checks whether a circular inheritance path ofC >-> C
is convertible with the identity function or not, then report it as an ambiguous path if it is not. The new mechanism does not report ambiguous paths that are redundant with others. For example, checking the ambiguity of[f; g]
and[f'; g]
is redundant with that of[f]
and[f']
thus will not be reported (#11258, by Kazuhiko Sakaguchi).Changed: Several commands (
Search
,About
, ...) now print the implicit arguments in brackets when printing types (#11795, by Simon Boulier).Changed: The warning when using
Require
inside a section moved from thedeprecated
category to thefragile
category, because there is no plan to remove the functionality at this time (#11972, by Gaëtan Gilbert).Changed:
Redirect
now obeys thePrinting Width
andPrinting Depth
options (#12358, by Emilio Jesus Gallego Arias).Removed: Recursive OCaml loadpaths are not supported anymore; the command
Add Rec ML Path
has been removed;Add ML Path
is now the preferred one. We have also dropped support for the non-qualified version of theAdd LoadPath
command, that is to say, theAdd LoadPath dir
version; now, you must always specify a prefix now usingAdd Loadpath dir as Prefix
(#11618, by Emilio Jesus Gallego Arias).Removed: undocumented
Chapter
command. UseSection
instead (#11746, by Théo Zimmermann).Removed:
SearchAbout
command that was deprecated since 8.5. UseSearch
instead (#11944, by Jim Fehrle).Deprecated: Declaration of arbitrary terms as hints. Global references are now preferred (#7791, by Pierre-Marie Pédrot).
Deprecated:
SearchHead
in favor of the newheadconcl:
clause ofSearch
(part of #8855, by Théo Zimmermann).Added:
Print Canonical Projections
can now take constants as arguments and prints only the unification rules that involve or are synthesized from the given constants (#10747, by Kazuhiko Sakaguchi).Added: A section variable introduced with
Let
can be declared as aCanonical Structure
(#11164, by Enrico Tassi).Added: Support for universe bindings and universe contrainsts in
Let
definitions (#11534, by Théo Zimmermann).Added: Support for new clauses
hyp:
,headhyp:
,concl:
,headconcl:
,head:
andis:
inSearch
. Support for complex search queries combining disjunctions, conjunctions and negations (#8855, by Hugo Herbelin, with ideas from Cyril Cohen and help from Théo Zimmermann).Fixed: A printing bug in the presence of elimination principles with local definitions (#12295, by Hugo Herbelin; fixes #12233).
Fixed: Anomalies with
Show Proof
(#12296, by Hugo Herbelin; fixes #12234).
Tools¶
Changed: Internal options and behavior of
coqdep
.coqdep
no longer works as a replacement forocamldep
, thus.ml
files are not supported as input. Also, several deprecated options have been removed:-w
,-D
,-mldep
,-prefix
,-slash
, and-dumpbox
. Passing-boot
tocoqdep
will not load any path by default now,-R/-Q
should be used instead (#11523 and #11589, by Emilio Jesus Gallego Arias).Changed: The order in which the require flags
-ri
,-re
,-rfrom
, etc. and the option flags-set
,-unset
are given now matters. In particular, it is now possible to interleave the loading of plugins and the setting of options by choosing the right order for these flags. The load flags-l
and-lv
are still processed afterward for now (#11851 and #12097, by Lasse Blaauwbroek).Changed: The
cleanall
target of a makefile generated bycoq_makefile
now erases.lia.cache
and.nia.cache
(#12006, by Olivier Laurent).Changed: The output of
make TIMED=1
(and therefore the timing targets such asprint-pretty-timed
andprint-pretty-timed-diff
) now displays the full name of the output file being built, rather than the stem of the rule (which was usually the filename without the extension, but in general could be anything for user-defined rules involving%
) (#12126, by Jason Gross).Changed: When passing
TIMED=1
tomake
with either Coq's own makefile or acoq_makefile
-made makefile, timing information is now printed for OCaml files as well (#12211, by Jason Gross).Changed: The pretty-timed scripts and targets now print a newline at the end of their tables, rather than creating text with no trailing newline (#12368, by Jason Gross).
Removed: The
-load-ml-source
and-load-ml-object
command-line options have been removed; their use was very limited, you can achieve the same adding additional object files in the linking step or using a plugin (#11409, by Emilio Jesus Gallego Arias).Removed: The confusingly-named
-require
command-line option, which was deprecated since 8.11. Use the equivalent-require-import
/-ri
options instead (#12005, by Théo Zimmermann).Deprecated:
-cumulative-sprop
command-line flag in favor of the newCumulative StrictProp
flag (#12034, by Gaëtan Gilbert).Added: A new documentation environment
details
to make certain portion of a Coq document foldable. See Hiding / Showing parts of the source (#10592, by Thomas Letan).Added: The
make-both-single-timing-files.py
script now accepts a--fuzz=N
parameter on the command line which determines how many characters two lines may be offset in the "before" and "after" timing logs while still being considered the same line. When invoking this script via theprint-pretty-single-time-diff
target in aMakefile
made bycoq_makefile
, you can set this argument by passingTIMING_FUZZ=N
tomake
(#11302, by Jason Gross).Added: The
make-one-time-file.py
andmake-both-time-files.py
scripts now accept a--real
parameter on the command line to print real times rather than user times in the tables. Themake-both-single-timing-files.py
script accepts a--user
parameter to use user times. When invoking these scripts via theprint-pretty-timed
orprint-pretty-timed-diff
orprint-pretty-single-time-diff
targets in aMakefile
made bycoq_makefile
, you can set this argument by passingTIMING_REAL=1
(to pass--real
) orTIMING_REAL=0
(to pass--user
) tomake
(#11302, by Jason Gross).Added: Coq's build system now supports both
TIMING_FUZZ
,TIMING_SORT_BY
, andTIMING_REAL
just like aMakefile
made bycoq_makefile
(#11302, by Jason Gross).Added: The
make-one-time-file.py
andmake-both-time-files.py
scripts now include peak memory usage information in the tables (can be turned off by the--no-include-mem
command-line parameter), and a--sort-by-mem
parameter to sort the tables by memory rather than time. When invoking these scripts via theprint-pretty-timed
orprint-pretty-timed-diff
targets in aMakefile
made bycoq_makefile
, you can set this argument by passingTIMING_INCLUDE_MEM=0
(to pass--no-include-mem
) andTIMING_SORT_BY_MEM=1
(to pass--sort-by-mem
) tomake
(#11606, by Jason Gross).Added: Coq's build system now supports both
TIMING_INCLUDE_MEM
andTIMING_SORT_BY_MEM
just like aMakefile
made bycoq_makefile
(#11606, by Jason Gross).Added: New
coqc
/coqtop
option-boot
that will not bind theCoq
library prefix by default (#11617, by Emilio Jesus Gallego Arias).Added: Definitions in coqdoc link to themselves, giving access in html to their own url (#12026, by Hugo Herbelin; granting #7093).
Added: Hyperlinks on bound variables in coqdoc (#12033, by Hugo Herbelin; it incidentally fixes #7697).
Added: Highlighting of link targets in coqdoc (#12091, by Hugo Herbelin).
Fixed: The various timing targets for Coq's standard library now correctly display and label the "before" and "after" columns, rather than mixing them up (#11302 fixes #11301, by Jason Gross).
Fixed: The sorting order of the timing script
make-both-time-files.py
and the targetprint-pretty-timed-diff
is now deterministic even when the sorting order isabsolute
ordiff
; previously the relative ordering of two files with identical times was non-deterministic (#11606, by Jason Gross).Fixed: Fields of a record tuple now link in coqdoc to their definition (#12027, fixes #3415, by Hugo Herbelin).
Fixed:
coqdoc
now reports the location of a mismatched opening[[
instead of throwing an uninformative exception (#12037, fixes #9670, by Xia Li-yao).Fixed: coqchk incorrectly reporting names from opaque modules as axioms (#12076, by Pierre Roux; fixes #5030).
Fixed: coq_makefile-generated
Makefile
spretty-timed-diff
target no longer raises Python exceptions in the rare corner case where the log of times contains no files (#12388, fixes #12387, by Jason Gross).
CoqIDE¶
Standard library¶
Changed: Notations
[|term|]
and[||term||]
for morphisms from 63-bit integers toZ
andzn2z int
have been removed in favor ofφ(term)
andΦ(term)
respectively. These notations were breaking Ltac parsing (#11686, by Maxime Dénès).Changed: The names of
Sorted_sort
andLocallySorted_sort
inCoq.Sorting.MergeSort
have been swapped to appropriately reflect their meanings (#11885, by Lysxia).Changed: Notations
<=?
and<?
fromCoq.Structures.Orders
andCoq.Sorting.Mergesort.NatOrder
are now at level 70 rather than 35, so as to be compatible with the notations defined everywhere else in the standard library. This may require re-parenthesizing some expressions. These notations were breaking the ability to import modules from the standard library that were otherwise compatible (fixes #11890, #11891, by Jason Gross).Changed: The level of
≡
inCoq.Numbers.Cyclic.Int63.Int63
is now 70, no associativity, in line with=
. Note that this is a minor incompatibility with developments that declare their own≡
notation and importInt63
(fixes #11905, #11909, by Jason Gross).Changed: No longer re-export
ListNotations
fromProgram
(Program.Syntax
) (#11992, by Antonio Nikishaev).Changed: It is now possible to import the
nsatz
machinery without transitively depending on the axioms of the real numbers nor of classical logic by loadingCoq.nsatz.NsatzTactic
rather thanCoq.nsatz.Nsatz
. Note that some constants have changed kernel names, living inCoq.nsatz.NsatzTactic
rather thanCoq.nsatz.Nsatz
; this might cause minor incompatibilities that can be fixed by actually runningImport Nsatz
rather than relying on absolute names (#12073, by Jason Gross; fixes #5445).Changed: new lemma
NoDup_incl_NoDup
inList.v
to remove useless hypothesisNoDup l'
inSorting.Permutation.NoDup_Permutation_bis
(#12120, by Olivier Laurent).Changed:
Fixpoints
of the standard library without a recursive call turned into ordinaryDefinitions
(#12121, by Hugo Herbelin; fixes #11903).Deprecated:
Bool.leb
in favor ofBool.le
. The definition ofBool.le
is made local to avoid conflicts withNat.le
. As a consequence, previous calls toleb
based on importingBool
should now be qualified intoBool.le
even ifBool
is imported (#12162, by Olivier Laurent).Added: Theorem
bezout_comm
for natural numbers (#11127, by Daniel de Rauglaudre).Added
rew dependent
notations for the dependent version ofrew
inCoq.Init.Logic.EqNotations
to improve the display and parsing ofmatch
statements onLogic.eq
(#11240, by Jason Gross).Added: Lemmas about lists:
properties of
In
:in_elt
,in_elt_inv
properties of
nth
:app_nth2_plus
,nth_middle
,nth_ext
properties of
last
:last_last
,removelast_last
properties of
remove
:remove_cons
,remove_app
,notin_remove
,in_remove
,in_in_remove
,remove_remove_comm
,remove_remove_eq
,remove_length_le
,remove_length_lt
properties of
concat
:in_concat
,remove_concat
properties of
map
andflat_map
:map_last
,map_eq_cons
,map_eq_app
,flat_map_app
,flat_map_ext
,nth_nth_nth_map
properties of
incl
:incl_nil_l
,incl_l_nil
,incl_cons_inv
,incl_app_app
,incl_app_inv
,remove_incl
,incl_map
,incl_filter
,incl_Forall_in_iff
properties of
NoDup
andnodup
:NoDup_rev
,NoDup_filter
,nodup_incl
properties of
Exists
andForall
:Exists_nth
,Exists_app
,Exists_rev
,Exists_fold_right
,incl_Exists
,Forall_nth
,Forall_app
,Forall_elt
,Forall_rev
,Forall_fold_right
,incl_Forall
,map_ext_Forall
,Exists_or
,Exists_or_inv
,Forall_and
,Forall_and_inv
,exists_Forall
,Forall_image
,concat_nil_Forall
,in_flat_map_Exists
,notin_flat_map_Forall
properties of
repeat
:repeat_cons
,repeat_to_concat
definitions and properties of
list_sum
andlist_max
:list_sum_app
,list_max_app
,list_max_le
,list_max_lt
misc:
elt_eq_unit
,last_length
,rev_eq_app
,removelast_firstn_len
,cons_seq
,seq_S
Added: Well-founded induction principles for
nat
:lt_wf_rect1
,lt_wf_rect
,gt_wf_rect
,lt_wf_double_rect
(#11335, by Olivier Laurent).Added:
remove'
andcount_occ'
over lists, alternatives toremove
andcount_occ
based onfilter
(#11350, by Yishuai Li).Added: Facts about
N.iter
andPos.iter
:N.iter_swap_gen
,N.iter_swap
,N.iter_succ
,N.iter_succ_r
,N.iter_add
,N.iter_ind
,N.iter_invariant
Pos.iter_succ_r
,Pos.iter_ind
(#11880, by Lysxia).
Added: Facts about
Permutation
:structure:
Permutation_refl'
,Permutation_morph_transp
compatibilities:
Permutation_app_rot
,Permutation_app_swap_app
,Permutation_app_middle
,Permutation_middle2
,Permutation_elt
,Permutation_Forall
,Permutation_Exists
,Permutation_Forall2
,Permutation_flat_map
,Permutation_list_sum
,Permutation_list_max
inversions:
Permutation_app_inv_m
,Permutation_vs_elt_inv
,Permutation_vs_cons_inv
,Permutation_vs_cons_cons_inv
,Permutation_map_inv
,Permutation_image
,Permutation_elt_map_inv
length-preserving definition by means of transpositions
Permutation_transp
with associated properties:Permutation_transp_sym
,Permutation_transp_equiv
,Permutation_transp_cons
,Permutation_Permutation_transp
,Permutation_ind_transp
(#11946, by Olivier Laurent).
Added: Notations for sigma types:
{ x & P & Q }
,{ ' pat & P }
,{ ' pat & P & Q }
(#11957, by Olivier Laurent).Added: Order relations
lt
andcompare
added inBool.Bool
. Order properties forbool
added inBool.BoolOrder
as well as two modulesBool_as_OT
andBool_as_DT
inStructures.OrdersEx
(#12008, by Olivier Laurent).Added: Properties of some operations on vectors:
nth_order
:nth_order_hd
,nth_order_tl
,nth_order_ext
replace
:nth_order_replace_eq
,nth_order_replace_neq
,replace_id
,replace_replace_eq
,replace_replace_neq
map
:map_id
,map_map
,map_ext_in
,map_ext
Forall
andForall2
:Forall_impl
,Forall_forall
,Forall_nth_order
,Forall2_nth_order
(#12014, by Olivier Laurent).
Added: Lemmas
orb_negb_l
,andb_negb_l
,implb_true_iff
,implb_false_iff
,implb_true_r
,implb_false_r
,implb_true_l
,implb_false_l
,implb_same
,implb_contrapositive
,implb_negb
,implb_curry
,implb_andb_distrib_r
,implb_orb_distrib_r
,implb_orb_distrib_l
in libraryBool
(#12018, by Hugo Herbelin).Added: Definition and properties of cyclic permutations / circular shifts:
CPermutation
(#12031, by Olivier Laurent).Added:
Structures.OrderedTypeEx.Ascii_as_OT
(#12044, by formalize.eth (formalize@protonmail.com)).Fixed: Rewrote
Structures.OrderedTypeEx.String_as_OT.compare
to avoid huge proof terms (#12044, by formalize.eth (formalize@protonmail.com); fixes #12015).
Reals library¶
Changed: Cleanup of names in the Reals theory: replaced
tan_is_inj
withtan_inj
and replacedatan_right_inv
withtan_atan
- compatibility notations are provided. Moved various auxiliary lemmas fromRatan.v
to more appropriate places (#9803, by Laurent Théry and Michael Soegtrop).Changed: Replace
CRzero
andCRone
byCR_of_Q 0
andCR_of_Q 1
inConstructiveReals
. Use implicit arguments forConstructiveReals
. MoveConstructiveReals
into new directoryAbstract
. Remove imports of implementations inside thoseAbstract
files. Move implementation by means of Cauchy sequences in new directoryCauchy
. Split filesConstructiveMinMax
andConstructivePower
.Warning
The constructive reals modules are marked as experimental.
Removed: Type
RList
has been removed. All uses have been replaced bylist R
. Functions fromRList
namedIn
,Rlength
,cons_Rlist
,app_Rlist
have also been removed as they are essentially the same asIn
,length
,app
, andmap
fromList
, modulo the following changes:RList.In x (RList.cons a l)
used to be convertible to(x = a) \/ RList.In x l
, butList.In x (a :: l)
is convertible to(a = x) \/ List.In l
. The equality is reversed.app_Rlist
andList.map
take arguments in different order.
(#11404, by Yves Bertot).
Added: inverse trigonometric functions
asin
andacos
with lemmas for the derivatives, bounds and special values of these functions; an extensive set of identities between trigonometric functions and their inverse functions; lemmas for the injectivity of sine and cosine; lemmas on the derivative of the inverse of decreasing functions and on the derivative of horizontally mirrored functions; various generic auxiliary lemmas and definitions forRsqr
,sqrt
,posreal
and others (#9803, by Laurent Théry and Michael Soegtrop).
Extraction¶
Added: Support for better extraction of strings in OCaml and Haskell:
ExtOcamlNativeString
provides bindings from the CoqString
type to the OCamlstring
type, and string literals can be extracted to literals, both in OCaml and Haskell (#10486, by Xavier Leroy, with help from Maxime Dénès, review by Hugo Herbelin).Fixed: In Haskell extraction with
ExtrHaskellString
, equality comparisons on strings and characters are now guaranteed to be uniquely well-typed, even in very polymorphic contexts underunsafeCoerce
; this is achieved by adding type annotations to the extracted code, and by makingExtrHaskellString
exportExtrHaskellBasic
(#12263, by Jason Gross, fixes #12257 and #12258).
Reference manual¶
Changed: The reference manual has been restructured to get a more logical organization. In the new version, there are fewer top-level chapters, and, in the HTML format, chapters are split into smaller pages. This is still a work in progress and further restructuring is expected in the next versions of Coq (CEP#43, implemented in #11601, #11871, #11914, #12148, #12172, #12239 and #12330, effort inspired by Matthieu Sozeau, led by Théo Zimmermann, with help and reviews of Jim Fehrle, Clément Pit-Claudel and others).
Changed: Most of the grammar is now presented using the notation mechanism that has been used to present commands and tactics since Coq 8.8 and which is documented in Syntax conventions (#11183, #11314, #11423, #11705, #11718, #11720, #11961 and #12103, by Jim Fehrle, reviewed by Théo Zimmermann).
Added: A glossary of terms and an index of attributes (#11869, #12150 and #12224, by Jim Fehrle and Théo Zimmermann, reviewed by Clément Pit-Claudel)
Added: A selector that allows switching between versions of the reference manual (#12286, by Clément Pit-Claudel).
Fixed: Most of the documented syntax has been thoroughly updated to make it accurate and easily understood. This was done using a semi-automated
doc_grammar
tool introduced for this purpose and through significant revisions to the text (#9884, #10614, #11314, #11423, #11705, #11718, #11720 #11797, #11913, #11958, #11960, #11961 and #12103, by Jim Fehrle, reviewed by Théo Zimmermann and Jason Gross).
Infrastructure and dependencies¶
Changed: Minimal versions of dependencies for building the reference manual: now requires Sphinx >= 2.3.1 & < 3.0.0, sphinx_rtd_theme 0.4.3+ and sphinxcontrib-bibtex 0.4.2+.
Warning
The reference manual is known not to build properly with Sphinx 3.
(#12224, by Jim Fehrle and Théo Zimmermann).
Removed: Python 2 is no longer required in any part of the codebase (#11245, by Emilio Jesus Gallego Arias).
Changes in 8.12.0¶
Notations
Added: Simultaneous definition of terms and notations now support custom entries (#12523, fixes #11121 by Maxime Dénès).
Fixed: Printing bug with notations for n-ary applications used with applied references (#12683, fixes #12682, by Hugo Herbelin).
Tactics
Fixed:
typeclasses eauto
(and discriminated hint bases) now correctly classify local variables as being unfoldable (#12572, fixes #12571, by Pierre-Marie Pédrot).
Tactic language
Fixed: Excluding occurrences was causing an anomaly in tactics (e.g.,
pattern _ at L
whereL
is-2
) (#12541, fixes #12228, by Pierre Roux).Fixed: Parsing of multi-parameters Ltac2 types (#12594, fixes #12595, by Pierre-Marie Pédrot).
SSReflect
Fixed: Do not store the full environment inside ssr ast_closure_term (#12708, fixes #12707, by Pierre-Marie Pédrot).
Commands and options
Fixed: Properly report the mismatched magic number of vo files (#12677, fixes #12513, by Pierre-Marie Pédrot).
Changed: Arbitrary hints have been undeprecated, and their definition now triggers a standard warning instead (#12678, fixes #11970, by Pierre-Marie Pédrot).
CoqIDE
Fixed: CoqIDE no longer exits when trying to open a file whose name is not a valid identifier (#12562, fixes #10988, by Vincent Laporte).
Infrastructure and dependencies
Changes in 8.12.1¶
Kernel
Fixed: Incompleteness of conversion checking on problems involving η-expansion and cumulative universe polymorphic inductive types (#12738, fixes #7015, by Gaëtan Gilbert).
Fixed: Polymorphic side-effects inside monomorphic definitions were incorrectly handled as not inlined. This allowed deriving an inconsistency (#13331, fixes #13330, by Pierre-Marie Pédrot).
Notations
Fixed: Undetected collision between a lonely notation and a notation in scope at printing time (#12946, fixes the first part of #12908, by Hugo Herbelin).
Fixed: Printing of notations in custom entries with variables not mentioning an explicit level (#13026, fixes #12775 and #13018, by Hugo Herbelin).
Tactics
Added:
replace
andinversion
support registration of acore.identity
-like equality inType
, such as HoTT'spath
(#12847, partially fixes #12846, by Hugo Herbelin).Fixed: Anomaly with
injection
involving artificial dependencies disappearing by reduction (#12816, fixes #12787, by Hugo Herbelin).
Tactic language
Fixed: Miscellaneous issues with locating tactic errors (#13247, fixes #12773 and #12992, by Hugo Herbelin).
SSReflect
Fixed: Regression in error reporting after
case
. A generic error message "Could not fill dependent hole in apply" was reported for any error followingcase
orelim
(#12857, fixes #12837, by Enrico Tassi).
Commands and options
Fixed: Failures of
Search
in the presence of primitive projections (#13301, fixes #13298, by Hugo Herbelin).Fixed:
Search
supports filtering on parts of identifiers which are not proper identifiers themselves, such as"1"
(#13351, fixes #13349, by Hugo Herbelin).
Tools
Fixed: Special symbols now escaped in the index produced by coqdoc, avoiding collision with the syntax of the output format (#12754, fixes #12752, by Hugo Herbelin).
Fixed: The
details
environment added in the 8.12 release can now be used as advertised in the reference manual (#12772, by Thomas Letan).Fixed: Targets such as
print-pretty-timed
incoq_makefile
-madeMakefile
s no longer error in rare cases where--output-sync
is not passed to make and the timing output gets interleaved in just the wrong way (#13063, fixes #13062, by Jason Gross).
CoqIDE
Fixed: View menu "Display parentheses" (#12794 and #13067, fixes #12793, by Jean-Christophe Léchenet and Hugo Herbelin).
Infrastructure and dependencies
Changes in 8.12.2¶
Notations
Fixed: 8.12 regression causing notations mentioning a coercion to be ignored (#13436, fixes #13432, by Hugo Herbelin).
Tactics
Version 8.11¶
Summary of changes¶
The main changes brought by Coq version 8.11 are:
Ltac2, a new tactic language for writing more robust larger scale tactics, with built-in support for datatypes and the multi-goal tactic monad.
Primitive floats are integrated in terms and follow the binary64 format of the IEEE 754 standard, as specified in the
Coq.Float.Floats
library.Cleanups of the section mechanism, delayed proofs and further restrictions of template polymorphism to fix soundness issues related to universes.
New unsafe flags to disable locally guard, positivity and universe checking. Reliance on these flags is always printed by
Print Assumptions
.Fixed bugs of
Export
andImport
that can have a significant impact on user developments (common source of incompatibility!).New interactive development method based on
vos
interface files, allowing to work on a file without recompiling the proof parts of their dependencies.New
Arguments
annotation for bidirectional type inference configuration for reference (e.g. constants, inductive) applications.New refine attribute for
Instance
can be used instead of the removedRefine Instance Mode
.Generalization of the
under
andover
tactics of SSReflect to arbitrary relations.Revision of the
Coq.Reals
library, its axiomatisation and instances of the constructive and classical real numbers.
Additionally, while the omega
tactic is not yet deprecated in
this version of Coq, it should soon be the case and we already
recommend users to switch to lia
in new proof scripts.
The dev/doc/critical-bugs
file documents the known critical bugs
of Coq and affected releases. See the Changes in 8.11+beta1
section and following sections for the detailed list of changes,
including potentially breaking changes marked with Changed.
Coq's documentation is available at https://coq.github.io/doc/v8.11/api (documentation of the ML API), https://coq.github.io/doc/v8.11/refman (reference manual), and https://coq.github.io/doc/v8.11/stdlib (documentation of the standard library).
Maxime Dénès, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Michael Soegtrop and Théo Zimmermann worked on maintaining and improving the continuous integration system and package building infrastructure.
The opam repository for Coq packages has been maintained by Guillaume Claret, Karl Palmskog, Matthieu Sozeau and Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
The 61 contributors to this version are Michael D. Adams, Guillaume Allais, Helge Bahmann, Langston Barrett, Guillaume Bertholon, Frédéric Besson, Simon Boulier, Michele Caci, Tej Chajed, Arthur Charguéraud, Cyril Cohen, Frédéric Dabrowski, Arthur Azevedo de Amorim, Maxime Dénès, Nikita Eshkeev, Jim Fehrle, Emilio Jesús Gallego Arias, Paolo G. Giarrusso, Gaëtan Gilbert, Georges Gonthier, Jason Gross, Samuel Gruetter, Armaël Guéneau, Hugo Herbelin, Florent Hivert, Jasper Hugunin, Shachar Itzhaky, Jan-Oliver Kaiser, Robbert Krebbers, Vincent Laporte, Olivier Laurent, Samuel Lelièvre, Nicholas Lewycky, Yishuai Li, Jose Fernando Lopez Fernandez, Andreas Lynge, Kenji Maillard, Erik Martin-Dorel, Guillaume Melquiond, Alexandre Moine, Oliver Nash, Wojciech Nawrocki, Antonio Nikishaev, Pierre-Marie Pédrot, Clément Pit-Claudel, Lars Rasmusson, Robert Rand, Talia Ringer, JP Rodi, Pierre Roux, Kazuhiko Sakaguchi, Vincent Semeria, Michael Soegtrop, Matthieu Sozeau, spanjel, Claude Stolze, Enrico Tassi, Laurent Théry, James R. Wilcox, Xia Li-yao, Théo Zimmermann
Many power users helped to improve the design of the new features via the issue and pull request system, the Coq development mailing list, the coq-club@inria.fr mailing list or the Discourse forum. It would be impossible to mention exhaustively the names of everybody who to some extent influenced the development.
Version 8.11 is the sixth release of Coq developed on a time-based development cycle. Its development spanned 3 months from the release of Coq 8.10. Pierre-Marie Pédrot is the release manager and maintainer of this release, assisted by Matthieu Sozeau. This release is the result of 2000+ commits and 300+ PRs merged, closing 75+ issues.
Changes in 8.11+beta1¶
Kernel
Added: A built-in support of floating-point arithmetic, allowing one to devise efficient reflection tactics involving numerical computation. Primitive floats are added in the language of terms, following the binary64 format of the IEEE 754 standard, and the related operations are implemented for the different reduction engines of Coq by using the corresponding processor operators in rounding-to-nearest-even. The properties of these operators are axiomatized in the theory
Coq.Floats.FloatAxioms
which is part of the libraryCoq.Floats.Floats
. See Section Primitive Floats (#9867, closes #8276, by Guillaume Bertholon, Erik Martin-Dorel, Pierre Roux).Changed: Internal definitions generated by
abstract
-like tactics are now inlined inside universeQed
-terminated polymorphic definitions, similarly to what happens for their monomorphic counterparts, (#10439, by Pierre-Marie Pédrot).Fixed: Section data is now part of the kernel. Solves a soundness issue in interactive mode where global monomorphic universe constraints would be dropped when forcing a delayed opaque proof inside a polymorphic section. Also relaxes the nesting criterion for sections, as polymorphic sections can now appear inside a monomorphic one (#10664, by Pierre-Marie Pédrot).
Changed: Using
SProp
is now allowed by default, without needing to pass-allow-sprop
or useAllow StrictProp
(#10811, by Gaëtan Gilbert).
Specification language, type inference
Added: Annotation in
Arguments
for bidirectionality hints: it is now possible to tell type inference to use type information from the context once then
first arguments of an application are known. The syntax is:Arguments foo x y & z
. See Bidirectionality hints (#10049, by Maxime Dénès with help from Enrico Tassi).Added: Record fields can be annotated to prevent them from being used as canonical projections; see Canonical Structures for details (#10076, by Vincent Laporte).
Changed: Require parentheses around nested disjunctive patterns, so that pattern and term syntax are consistent; match branch patterns no longer require parentheses for notation at level 100 or more.
Warning
Incompatibilities
In
match p with (_, (0|1)) => ...
parentheses may no longer be omitted around0|1
.Notation
(p | q)
now potentially clashes with core pattern syntax, and should be avoided.-w disj-pattern-notation
flags suchNotation
.
See Extended pattern matching for details (#10167, by Georges Gonthier).
Changed:
Function
always opens a proof when used with ameasure
orwf
annotation, see Advanced recursive functions for the updated documentation (#10215, by Enrico Tassi).Changed: The legacy command
Add Morphism
always opens a proof and cannot be used inside a module type. In order to declare a module type parameter that happens to be a morphism, useDeclare Morphism
. See Deprecated syntax and backward incompatibilities for the updated documentation (#10215, by Enrico Tassi).Changed: The universe polymorphism setting now applies from the opening of a section. In particular, it is not possible anymore to mix polymorphic and monomorphic definitions in a section when there are no variables nor universe constraints defined in this section. This makes the behavior consistent with the documentation. (#10441, by Pierre-Marie Pédrot)
Added: The
Section
command now accepts the "universes" attribute. In addition to setting the section universe polymorphism, it also locally sets the universe polymorphic option inside the section (#10441, by Pierre-Marie Pédrot)Fixed:
Program Fixpoint
now usesex
andsig
to make telescopes involvingProp
types (#10758, by Gaëtan Gilbert, fixing #10757 reported by Xavier Leroy).Changed: Output of the
Print
andAbout
commands. Arguments meta-data is now displayed as the correspondingArguments
command instead of the human-targeted prose used in previous Coq versions. (#10985, by Gaëtan Gilbert).Added:
refine
attribute forInstance
, a more predictable version of the oldRefine Instance Mode
which unconditionally opens a proof (#10996, by Gaëtan Gilbert).Changed: The unsupported attribute error is now an error-by-default warning, meaning it can be disabled (#10997, by Gaëtan Gilbert).
Fixed: Bugs sometimes preventing to define valid (co)fixpoints with implicit arguments in the presence of local definitions, see #3282 (#11132, by Hugo Herbelin).
Example
The following features an implicit argument after a local definition. It was wrongly rejected.
- Definition f := fix f (o := true) {n : nat} m {struct m} := match m with 0 => 0 | S m' => f (n:=n+1) m' end.
- f is defined
Notations
Added: Numeral Notations now support sorts in the input to printing functions (e.g., numeral notations can be defined for terms containing things like
@cons Set nat nil
). (#9883, by Jason Gross).Added: The
Notation
andInfix
commands now support thedeprecated
attribute (#10180, by Maxime Dénès).Deprecated: The former
compat
annotation for notations is deprecated, and its semantics changed. It is now made equivalent to using adeprecated
attribute, and is no longer connected with the-compat
command-line flag (#10180, by Maxime Dénès).Changed: A simplification of parsing rules could cause a slight change of parsing precedences for the very rare users who defined notations with
constr
at level strictly between 100 and 200 and used these notations on the right-hand side of a cast operator (:
,<:
,<<:
) (#10963, by Théo Zimmermann, simplification initially noticed by Jim Fehrle).
Tactics
Added: Syntax
injection term as [= intropattern+ ]
as an alternative toinjection term as simple_intropattern+
using the standard injection intropattern syntax (#9288, by Hugo Herbelin).Changed: Reimplementation of the
zify
tactic. The tactic is more efficient and copes with dependent hypotheses. It can also be extended by redefining the tacticzify_post_hook
(#9856, fixes #8898, #7886, #9848 and #5155, by Frédéric Besson).Changed: The goal selector tactical
only
now checks that the goal range it is given is valid instead of ignoring goals out of the focus range (#10318, by Gaëtan Gilbert).Added: Flags
Lia Cache
,Nia Cache
andNra Cache
(#10765, by Frédéric Besson, see #10772 for use case).Added: The
zify
tactic is now aware ofZ.to_N
(#10774, grants #9162, by Kazuhiko Sakaguchi).Changed: The
assert_succeeds
andassert_fails
tactics now only run their tactic argument once, even if it has multiple successes. This prevents blow-up and looping from using multisuccess tactics withassert_succeeds
. (#10966 fixes #10965, by Jason Gross).Fixed: The
assert_succeeds
andassert_fails
tactics now behave correctly when their tactic fully solves the goal. (#10966 fixes #9114, by Jason Gross).
Tactic language
Added: Ltac2, a new version of the tactic language Ltac, that doesn't preserve backward compatibility, has been integrated in the main Coq distribution. It is still experimental, but we already recommend users of advanced Ltac to start using it and report bugs or request enhancements. See its documentation in the dedicated chapter (#10002, plugin authored by Pierre-Marie Pédrot, with contributions by various users, integration by Maxime Dénès, help on integrating / improving the documentation by Théo Zimmermann and Jim Fehrle).
Added: Ltac2 tactic notations with “constr” arguments can specify the notation scope for these arguments; see Notations for details (#10289, by Vincent Laporte).
Changed: White spaces are forbidden in the
&ident
syntax for ltac2 references that are described in Built-in quotations (#10324, fixes #10088, authored by Pierre-Marie Pédrot).
SSReflect
Added: Generalize tactics
under
andover
for any registered relation. More precisely, assume the given context lemma has typeforall f1 f2, .. -> (forall i, R1 (f1 i) (f2 i)) -> R2 f1 f2
. The first step performed byunder
(since Coq 8.10) amounts to calling the tacticrewrite
, which itself relies onsetoid_rewrite
if need be. So this step was already compatible with a double implication or setoid equality for the conclusion head symbolR2
. But a further step consists in tagging the generated subgoalR1 (f1 i) (?f2 i)
to protect it from unwanted evar instantiation, and getUnder_rel _ R1 (f1 i) (?f2 i)
that is displayed as'Under[ f1 i ]
. In Coq 8.10, this second (convenience) step was only performed whenR1
was Leibniz'eq
oriff
. Now, it is also performed for any relationR1
which has aRewriteRelation
instance (aRelationClasses.Reflexive
instance being also needed soover
can discharge the'Under[ _ ]
goal by instantiating the hidden evar.) This feature generalizing support for setoid-like relations is enabled as soon as we do bothRequire Import ssreflect.
andRequire Setoid.
Finally, a rewrite ruleUnderE
has been added if one wants to "unprotect" the evar, and instantiate it manually with another rule than reflexivity (i.e., without using theover
tactic nor theover
rewrite rule). See also Section Rewriting under binders (#10022, by Erik Martin-Dorel, with suggestions and review by Enrico Tassi and Cyril Cohen).Added: A
void
notation for the standard library empty type (Empty_set
) (#10932, by Arthur Azevedo de Amorim).Added: Lemma
inj_compr
tossr.ssrfun
(#11136, by Cyril Cohen).
Commands and options
Removed: Deprecated flag
Refine Instance Mode
(#9530, fixes #3632, #3890 and #4638 by Maxime Dénès, review by Gaëtan Gilbert).Changed:
Fail
does not catch critical errors (including "stack overflow") anymore (#10173, by Gaëtan Gilbert).Removed: Undocumented
Instance : !type
syntax (#10185, by Gaëtan Gilbert).Removed: Deprecated
Show Script
command (#10277, by Gaëtan Gilbert).Added: Unsafe commands to enable/disable guard checking, positivity checking and universes checking (providing a local
-type-in-type
). See Controlling Typing Flags (#10291 by Simon Boulier).Fixed: Two bugs in
Export
. This can have an impact on the behavior of theImport
command on libraries.Import A
whenA
importsB
which exportsC
was importingC
, whereasImport
is not transitive. Also, afterImport A B
, the import ofB
was sometimes incomplete (#10476, by Maxime Dénès).Warning
This is a common source of incompatibilities in projects migrating to Coq 8.11.
Changed: Output generated by
Printing Dependent Evars Line
flag used by the Prooftree tool in Proof General (#10489, closes #4504, #10399 and #10400, by Jim Fehrle).Added: Optionally highlight the differences between successive proof steps in the
Show Proof
command. Experimental; only available in coqtop and Proof General for now, may be supported in other IDEs in the future (#10494, by Jim Fehrle).Removed: Legacy commands
AddPath
,AddRecPath
, andDelPath
which were undocumented, broken variants ofAdd LoadPath
,Add Rec LoadPath
, andRemove LoadPath
(#11187, by Maxime Dénès and Théo Zimmermann).
Tools
Added:
coqc
now provides the ability to generate compiled interfaces. Usecoqc -vos foo.v
to skip all opaque proofs during the compilation offoo.v
, and output a file calledfoo.vos
. This feature is experimental. It enables working on a Coq file without the need to first compile the proofs contained in its dependencies (#8642 by Arthur Charguéraud, review by Maxime Dénès and Emilio Gallego).Added: Command-line options
-require-import
,-require-export
,-require-import-from
and-require-export-from
, as well as their shorthand,-ri
,-re
,-refrom
and -rifrom
. Deprecate confusing command line option-require
(#10245 by Hugo Herbelin, review by Emilio Gallego).Changed: Renamed
VDFILE
from.coqdeps.d
to.<CoqMakefile>.d
in thecoq_makefile
utility, where<CoqMakefile>
is the name of the output file given by the-o
option. In this way two generated makefiles can coexist in the same directory (#10947, by Kazuhiko Sakaguchi).Fixed:
coq_makefile
now supports environment variableCOQBIN
with no ending/
character (#11068, by Gaëtan Gilbert).
Standard library
Changed: Moved the
auto
hints of theOrderedType
module into a newordered_type
database (#9772, by Vincent Laporte).Removed: Deprecated modules
Coq.ZArith.Zlogarithm
andCoq.ZArith.Zsqrt_compat
(#9811, by Vincent Laporte).Added: Module
Reals.Cauchy.ConstructiveCauchyReals
defines constructive real numbers by Cauchy sequences of rational numbers (#10445, by Vincent Semeria, with the help and review of Guillaume Melquiond and Bas Spitters). This module is not meant to be imported directly, please importReals.Abstract.ConstructiveReals
instead.Added: New module
Reals.ClassicalDedekindReals
defines Dedekind real numbers as boolean-valued functions along with 3 logical axioms: limited principle of omniscience, excluded middle of negations, and functional extensionality. The exposed typeR
in moduleReals.Rdefinitions
now corresponds to these Dedekind reals, hidden behind an opaque module, which significantly reduces the number of axioms needed (seeReals.Rdefinitions
andReals.Raxioms
), while preserving backward compatibility. Classical Dedekind reals are a quotient of constructive reals, which allows to transport many constructive proofs to the classical case (#10827, by Vincent Semeria, based on discussions with Guillaume Melquiond, Bas Spitters and Hugo Herbelin, code review by Hugo Herbelin).Added: New lemmas on
combine
,filter
,nodup
,nth
, andnth_error
functions on lists (#10651, and #10731, by Oliver Nash).Changed: The lemma
filter_app
was moved to theList
module (#10651, by Oliver Nash).Added: Standard equivalence between weak excluded-middle and the classical instance of De Morgan's law, in module
ClassicalFacts
(#10895, by Hugo Herbelin).
Infrastructure and dependencies
Changed: Coq now officially supports OCaml 4.08. See
INSTALL
file for details (#10471, by Emilio Jesús Gallego Arias).
Changes in 8.11.0¶
Kernel
Changed: the native compilation (
native_compute
) now creates a directory to contain temporary files instead of putting them in the root of the system temporary directory (#11081, by Gaëtan Gilbert).Fixed: #11360. Broken section closing when a template polymorphic inductive type depends on a section variable through its parameters (#11361, by Gaëtan Gilbert).
Fixed: The type of
Set+1
would be computed to be itself, leading to a proof of False (#11422, by Gaëtan Gilbert).
Specification language, type inference
Changed: Heuristics for universe minimization to
Set
: only minimize flexible universes (#10657, by Gaëtan Gilbert with help from Maxime Dénès and Matthieu Sozeau).Fixed: A dependency was missing when looking for default clauses in the algorithm for printing pattern matching clauses (#11233, by Hugo Herbelin, fixing #11231, reported by Barry Jay).
Notations
Fixed:
Print Visibility
was failing in the presence of only-printing notations (#11276, by Hugo Herbelin, fixing #10750).Fixed: Recursive notations with custom entries were incorrectly parsing
constr
instead of custom grammars (#11311 by Maxime Dénès, fixes #9532, #9490).
Tactics
Changed: The tactics
eapply
,refine
and variants no longer allow shelved goals to be solved by typeclass resolution (#10762, by Matthieu Sozeau).Fixed: The optional string argument to
time
is now properly quoted underPrint Ltac
(#11203, fixes #10971, by Jason Gross)Fixed: Efficiency regression of
lia
introduced in 8.10 by PR #9725 (#11263, fixes #11063, and #11242, and #11270, by Frédéric Besson).Deprecated: The undocumented
omega with
tactic variant has been deprecated. Usinglia
is the recommended replacement, though the old semantics ofomega with *
can be recovered withzify; omega
(#11337, by Emilio Jesus Gallego Arias).Fixed For compatibility reasons, in 8.11,
zify
does not supportZ.pow_pos
by default. It can be enabled by explicitly loading the moduleZifyPow
(#11430 by Frédéric Besson fixes #11191).
Tactic language
Fixed: Syntax of tactic
cofix ... with ...
was broken since Coq 8.10 (#11241, by Hugo Herbelin).
Commands and options
Deprecated: The
-load-ml-source
and-load-ml-object
command line options have been deprecated; their use was very limited, you can achieve the same by adding object files in the linking step or by using a plugin (#11428, by Emilio Jesus Gallego Arias).
Tools
Fixed:
coqtop --version
was broken when called in the middle of an installation process (#11255, by Hugo Herbelin, fixing #11254).Deprecated: The
-quick
command is renamed to-vio
, for consistency with the new-vos
and-vok
flags. Usage of-quick
is now deprecated (#11280, by Arthur Charguéraud).Fixed:
coq_makefile
does not break when using theCAMLPKGS
variable together with an unpacked (mllib
) plugin (#11357, by Gaëtan Gilbert).Fixed:
coqdoc
with option-g
(Gallina only) now correctly prints commands with attributes (#11394, fixes #11353, by Karl Palmskog).
CoqIDE
Changed: CoqIDE now uses the GtkSourceView native implementation of the autocomplete mechanism (#11400, by Pierre-Marie Pédrot).
Standard library
Removed: Export of module
RList
inRanalysis
andRanalysis_reg
. ModuleRList
is still there but must be imported explicitly where required (#11396, by Michael Soegtrop).
Infrastructure and dependencies
Added: Build date can now be overridden by setting the
SOURCE_DATE_EPOCH
environment variable (#11227, by Bernhard M. Wiedemann).
Changes in 8.11.1¶
Kernel
Fixed: Allow more inductive types in
Unset Positivity Checking
mode (#11811, by SimonBoulier).
Notations
Fixed: Bugs in dealing with precedences of notations in custom entries (#11530, by Hugo Herbelin, fixing in particular #9517, #9519, #9521, #11331).
Added: In primitive floats, print a warning when parsing a decimal value that is not exactly a binary64 floating-point number. For instance, parsing 0.1 will print a warning whereas parsing 0.5 won't (#11859, by Pierre Roux).
CoqIDE
Infrastructure and dependencies
Added: Bump official OCaml support and CI testing to 4.10.0 (#11131, #11123, #11102, by Emilio Jesus Gallego Arias, Jacques-Henri Jourdan, Guillaume Melquiond, and Guillaume Munch-Maccagnoni).
Miscellaneous
Fixed:
Extraction Implicit
on the constructor of a record was leading to an anomaly (#11329, by Hugo Herbelin, fixes #11114).
Changes in 8.11.2¶
Kernel
Fixed: Using
Require
inside a section caused an anomaly when closing the section. (#11972, by Gaëtan Gilbert, fixing #11783, reported by Attila Boros).
Tactics
Fixed: Anomaly with induction schemes whose conclusion is not normalized (#12116, by Hugo Herbelin; fixes #12045)
Fixed: Loss of location of some tactic errors (#12223, by Hugo Herbelin; fixes #12152 and #12255).
Commands and options
Changed: Ignore -native-compiler option when built without native compute support (#12070, by Pierre Roux).
CoqIDE
Changed: CoqIDE now uses native window frames by default on Windows. The GTK window frames can be restored by setting the
GTK_CSD
environment variable to1
(#12060, fixes #11080, by Attila Gáspár).Fixed: New patch presumably fixing the random Coq 8.11 segfault issue with CoqIDE completion (#12068, by Hugo Herbelin, presumably fixing #11943).
Fixed: Highlighting style consistently applied to all three buffers of CoqIDE (#12106, by Hugo Herbelin; fixes #11506).
Version 8.10¶
Summary of changes¶
Coq version 8.10 contains two major new features: support for a native fixed-precision integer type and a new sort \(\SProp\) of strict propositions. It is also the result of refinements and stabilization of previous features, deprecations or removals of deprecated features, cleanups of the internals of the system and API, and many documentation improvements. This release includes many user-visible changes, including deprecations that are documented in the next subsection, and new features that are documented in the reference manual. Here are the most important user-visible changes:
Kernel:
A notion of primitive object was added to the calculus. Its first instance is primitive cyclic unsigned integers, axiomatized in module
UInt63
. See Section Primitive Integers. TheCoq.Numbers.Cyclic.Int31
library is deprecated (#6914, by Maxime Dénès, Benjamin Grégoire and Vincent Laporte, with help and reviews from many others).The \(\SProp\) sort of definitionally proof-irrelevant propositions was introduced. \(\SProp\) allows to mark proof terms as irrelevant for conversion, and is treated like \(\Prop\) during extraction. It is enabled using the
-allow-sprop
command-line flag or theAllow StrictProp
flag. See Chapter SProp (proof irrelevant propositions) (#8817, by Gaëtan Gilbert).The unfolding heuristic in termination checking was made more complete, allowing more constants to be unfolded to discover valid recursive calls. Performance regression may occur in Fixpoint declarations without an explicit
{struct}
annotation, since guessing the decreasing argument can now be more expensive (#9602, by Enrico Tassi).
Universes:
Added Subgraph variant to
Print Universes
. Try for instancePrint Universes Subgraph(sigT2.u1 sigT_of_sigT2.u1 projT3_eq.u1).
(#8451, by Gaëtan Gilbert).Added private universes for opaque polymorphic constants, see the documentation for the
Private Polymorphic Universes
flag, and unset it to get the previous behavior (#8850, by Gaëtan Gilbert).
Notations:
New command
String Notation
to register string syntax for custom inductive types (#8965, by Jason Gross).Experimental: Number Notations now parse decimal constants such as
1.02e+01
or10.2
. Parsers added forQ
andR
. In the rare case when such numeral notations were used in a development along withQ
orR
, they may have to be removed or disambiguated through explicit scope annotations (#8764, by Pierre Roux).
Ltac backtraces can be turned on using the
Ltac Backtrace
flag, which is off by default (#9142, fixes #7769 and #7385, by Pierre-Marie Pédrot).The tactics
lia
,nia
,lra
,nra
are now using a novel Simplex-based proof engine. In case of regression, unsetSimplex
to get the venerable Fourier-based engine (#8457, by Fréderic Besson).SSReflect:
New intro patterns:
temporary introduction:
=> +
block introduction:
=> [^ prefix ] [^~ suffix ]
fast introduction:
=> >
tactics as views:
=> /ltac:mytac
replace hypothesis:
=> {}H
See Section Introduction in the context (#6705, by Enrico Tassi, with help from Maxime Dénès, ideas coming from various users).
New tactic
under
to rewrite under binders, given an extensionality lemma:It can take occurrence switches, contextual patterns, and intro patterns:
under {2}[in RHS]eq_big => [i|i ?]
(#9651, by Erik Martin-Dorel and Enrico Tassi).
Combined Scheme
now works when inductive schemes are generated in sort \(\Type\). It used to be limited to sortProp
(#7634, by Théo Winterhalter).A new registration mechanism for reference from ML code to Coq constructs has been added (#186, by Emilio Jesús Gallego Arias, Maxime Dénès and Vincent Laporte).
CoqIDE:
CoqIDE now depends on gtk+3 and lablgtk3 instead of gtk+2 and lablgtk2. The INSTALL file available in the Coq sources has been updated to list the new dependencies (#9279, by Hugo Herbelin, with help from Jacques Garrigue, Emilio Jesús Gallego Arias, Michael Sogetrop and Vincent Laporte).
Smart input for Unicode characters. For example, typing
\alpha
thenShift+Space
will insert the greek letter alpha. A larger number of default bindings are provided, following the latex naming convention. Bindings can be customized, either globally, or on a per-project basis. See Section Bindings for input of Unicode symbols for details (#8560, by Arthur Charguéraud).
Infrastructure and dependencies:
Coq 8.10 requires OCaml >= 4.05.0, bumped from 4.02.3 See the
INSTALL
file for more information on dependencies (#7522, by Emilio Jesús Gallego Arías).Coq 8.10 doesn't need Camlp5 to build anymore. It now includes a fork of the core parsing library that Coq uses, which is a small subset of the whole Camlp5 distribution. In particular, this subset doesn't depend on the OCaml AST, allowing easier compilation and testing on experimental OCaml versions. Coq also ships a new parser
coqpp
that plugin authors must switch to (#7902, #7979, #8161, #8667, and #8945, by Pierre-Marie Pédrot and Emilio Jesús Gallego Arias).The Coq developers would like to thank Daniel de Rauglaudre for many years of continued support.
Coq now supports building with Dune, in addition to the traditional Makefile which is scheduled for deprecation (#6857, by Emilio Jesús Gallego Arias, with help from Rudi Grinberg).
Experimental support for building Coq projects has been integrated in Dune at the same time, providing an improved experience for plugin developers. We thank the Dune team for their work supporting Coq.
Version 8.10 also comes with a bunch of smaller-scale changes and improvements regarding the different components of the system, including many additions to the standard library (see the next subsection for details).
On the implementation side, the dev/doc/changes.md
file documents
the numerous changes to the implementation and improvements of
interfaces. The file provides guidelines on porting a plugin to the new
version and a plugin development tutorial originally made by Yves Bertot
is now in doc/plugin_tutorial
. The dev/doc/critical-bugs
file
documents the known critical bugs of Coq and affected releases.
The efficiency of the whole system has seen improvements thanks to contributions from Gaëtan Gilbert, Pierre-Marie Pédrot, and Maxime Dénès.
Maxime Dénès, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Michael Soegtrop, Théo Zimmermann worked on maintaining and improving the continuous integration system and package building infrastructure. Coq is now continuously tested against the OCaml trunk, in addition to the oldest supported and latest OCaml releases.
Coq's documentation for the development branch is now deployed
continuously at https://coq.github.io/doc/master/api (documentation of
the ML API), https://coq.github.io/doc/master/refman (reference
manual), and https://coq.github.io/doc/master/stdlib (documentation of
the standard library). Similar links exist for the v8.10
branch.
The opam repository for Coq packages has been maintained by Guillaume Melquiond, Matthieu Sozeau, Enrico Tassi (who migrated it to opam 2) with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
The 61 contributors to this version are Tanaka Akira, Benjamin Barenblat, Yves Bertot, Frédéric Besson, Lasse Blaauwbroek, Martin Bodin, Joachim Breitner, Tej Chajed, Frédéric Chapoton, Arthur Charguéraud, Cyril Cohen, Lukasz Czajka, David A. Dalrymple, Christian Doczkal, Maxime Dénès, Andres Erbsen, Jim Fehrle, Emilio Jesus Gallego Arias, Gaëtan Gilbert, Matěj Grabovský, Simon Gregersen, Jason Gross, Samuel Gruetter, Hugo Herbelin, Jasper Hugunin, Mirai Ikebuchi, Chantal Keller, Matej Košík, Sam Pablo Kuper, Vincent Laporte, Olivier Laurent, Larry Darryl Lee Jr, Nick Lewycky, Yao Li, Yishuai Li, Assia Mahboubi, Simon Marechal, Erik Martin-Dorel, Thierry Martinez, Guillaume Melquiond, Kayla Ngan, Karl Palmskog, Pierre-Marie Pédrot, Clément Pit-Claudel, Pierre Roux, Kazuhiko Sakaguchi, Ryan Scott, Vincent Semeria, Gan Shen, Michael Soegtrop, Matthieu Sozeau, Enrico Tassi, Laurent Théry, Kamil Trzciński, whitequark, Théo Winterhalter, Xia Li-yao, Beta Ziliani and Théo Zimmermann.
Many power users helped to improve the design of the new features via the issue and pull request system, the Coq development mailing list, the coq-club@inria.fr mailing list or the new Discourse forum. It would be impossible to mention exhaustively the names of everybody who to some extent influenced the development.
Version 8.10 is the fifth release of Coq developed on a time-based development cycle. Its development spanned 6 months from the release of Coq 8.9. Vincent Laporte is the release manager and maintainer of this release. This release is the result of ~2500 commits and ~650 PRs merged, closing 150+ issues.
Other changes in 8.10+beta1¶
Command-line tools and options:
The use of
coqtop
as a compiler has been deprecated, in favor ofcoqc
. Consequently option-compile
will stop to be accepted in the next release.coqtop
is now reserved to interactive use (#9095, by Emilio Jesús Gallego Arias).New option
-topfile filename
, which will set the current module name (à la-top
) based on the filename passed, taking into account the proper-R
/-Q
options. For example, given-R Foo foolib
using-topfile foolib/bar.v
will set the module name toFoo.Bar
. CoqIDE now properly sets the module name for a given file based on its path (#8991, closes #8989, by Gaëtan Gilbert).Experimental: Coq flags and options can now be set on the command-line, e.g.
-set "Universe Polymorphism=true"
(#9876, by Gaëtan Gilbert).The
-native-compiler
flag ofcoqc
andcoqtop
now takes an argument which can have three values:no
disables native_computeyes
enables native_compute and precompiles.v
files to native codeondemand
enables native_compute but compiles code only whennative_compute
is called
The default value is
ondemand
. Note that this flag now has priority over the configure flag of the same name.A new
-bytecode-compiler
flag forcoqc
andcoqtop
controls whether conversion can use the VM. The default value isyes
.(#8870, by Maxime Dénès)
The pretty timing diff scripts (flag
TIMING=1
to acoq_makefile
-madeMakefile
, alsotools/make-both-single-timing-files.py
,tools/make-both-time-files.py
, andtools/make-one-time-file.py
) now correctly support non-UTF-8 characters in the output ofcoqc
/make
as well as printing to stdout, on both python2 and python3 (#9872, closes #9767 and #9705, by Jason Gross)coq_makefile's install target now errors if any file to install is missing (#9906, by Gaëtan Gilbert).
Preferences from
coqide.keys
are no longer overridden by modifiers preferences incoqiderc
(#10014, by Hugo Herbelin).
Specification language, type inference:
Fixing a missing check in interpreting instances of existential variables that are bound to local definitions. Might exceptionally induce an overhead if the cost of checking the conversion of the corresponding definitions is additionally high (#8217, closes #8215, by Hugo Herbelin).
A few improvements in inference of the return clause of
match
that can exceptionally introduce incompatibilities. This can be solved by writing an explicitreturn
clause, sometimes even simply an explicitreturn _
clause (#262, by Hugo Herbelin).Using non-projection values with the projection syntax is not allowed. For instance
0.(S)
is not a valid way to writeS 0
. Projections from non-primitive (emulated) records are allowed with warning "nonprimitive-projection-syntax" (#8829, by Gaëtan Gilbert).An option and attributes to control the automatic decision to declare an inductive type as template polymorphic were added. Warning "auto-template" (off by default) can trigger when an inductive is automatically declared template polymorphic without the attribute.
Inductive types declared by Funind will never be template polymorphic.
(#8488, by Gaëtan Gilbert)
Notations:
New command
Declare Scope
to explicitly declare a scope name before any use of it. Implicit declaration of a scope at the time ofBind Scope
,Delimit Scope
,Undelimit Scope
, orNotation
is deprecated (#7135, by Hugo Herbelin).Various bugs have been fixed (e.g. #9214 on removing spurious parentheses on abbreviations shortening a strict prefix of an application, by Hugo Herbelin).
Number Notation
now support inductive types in the input to printing functions (e.g., numeral notations can be defined for terms containing things like@cons nat O O
), and parsing functions now fully normalize terms including parameters of constructors (so that, e.g., a numeral notation whose parsing function outputs a proof ofNat.gcd x y = 1
will no longer fail to parse due to containing the constantNat.gcd
in the parameter-argument ofeq_refl
) (#9874, closes #9840 and #9844, by Jason Gross).Deprecated compatibility notations have actually been removed. Uses of these notations are generally easy to fix thanks to the hint contained in the deprecation warning emitted by Coq 8.8 and 8.9. For projects that require more than a handful of such fixes, there is a script that will do it automatically, using the output of
coqc
(#8638, by Jason Gross).Allow inspecting custom grammar entries by
Print Custom Grammar
(#10061, fixes #9681, by Jasper Hugunin, review by Pierre-Marie Pédrot and Hugo Herbelin).
The quote plugin was removed. If some users are interested in maintaining this plugin externally, the Coq development team can provide assistance for extracting the plugin and setting up a new repository (#7894, by Maxime Dénès).
Ltac:
Tactic names are no longer allowed to clash, even if they are not defined in the same section. For example, the following is no longer accepted:
Ltac foo := idtac. Section S. Ltac foo := fail. End S.
(#8555, by Maxime Dénès).Names of existential variables occurring in Ltac functions (e.g.
?[n]
or?n
in terms - not in patterns) are now interpreted the same way as other variable names occurring in Ltac functions (#7309, by Hugo Herbelin).
Tactics:
Removed the deprecated
romega
tactic (#8419, by Maxime Dénès and Vincent Laporte).Hint declaration and removal should now specify a database (e.g.
Hint Resolve foo : database
). When the database name is omitted, the hint is added to thecore
database (as previously), but a deprecation warning is emitted (#8987, by Maxime Dénès).There are now tactics in
PreOmega.v
calledZ.div_mod_to_equations
,Z.quot_rem_to_equations
, andZ.to_euclidean_division_equations
(which combines thediv_mod
andquot_rem
variants) which allowlia
,nia
, etc to supportZ.div
andZ.modulo
(Z.quot
andZ.rem
, respectively), by posing the specifying equation forZ.div
andZ.modulo
before replacing them with atoms (#8062, by Jason Gross).The syntax of the
autoapply
tactic was fixed to conform with preexisting documentation: it now takes awith
clause instead of ausing
clause (#9524, closes #7632, by Théo Zimmermann).Modes are now taken into account by
typeclasses eauto
for local hypotheses (#9996, fixes #5752, by Maxime Dénès, review by Pierre-Marie Pédrot).New variant
change_no_check
ofchange
, usable as a documented replacement ofconvert_concl_no_check
(#10012, #10017, #10053, and #10059, by Hugo Herbelin and Paolo G. Giarrusso).The simplified value returned by
field_simplify
is not always a fraction anymore. When the denominator is1
, it returnsx
while previously it was returningx/1
. This change could break codes that were post-processing application offield_simplify
to get rid of thesex/1
(#9854, by Laurent Théry, with help from Michael Soegtrop, Maxime Dénès, and Vincent Laporte).
SSReflect:
Clear discipline made consistent across the entire proof language. Whenever a clear switch
{x..}
comes immediately before an existing proof context entry (used as a view, as a rewrite rule or as name for a new context entry) then such entry is cleared too.E.g. The following sentences are elaborated as follows (when H is an existing proof context entry):
=> {x..} H
->=> {x..H} H
=> {x..} /H
->=> /v {x..H}
rewrite {x..} H
->rewrite E {x..H}
(#9341, by Enrico Tassi).
inE
now expandsy in r x
whenr
is asimpl_rel
. New{pred T}
notation for apred T
alias in thepred_sort
coercion class, simplifiedpredType
interface:pred_class
andmkPredType
deprecated,{pred T}
andPredType
should be used instead.if c return t then ...
now expectsc
to be a variable bound int
. NewnonPropType
interface matching types that do _not_ have sortProp
. Newrelpre R f
definition for the preimage of a relation R under f (#9995, by Georges Gonthier).
Commands:
Binders for an
Instance
now act more like binders for aTheorem
. Names may not be repeated, and may not overlap with section variable names (#8820, closes #8791, by Jasper Hugunin).Removed the deprecated
Implicit Tactic
family of commands (#8779, by Pierre-Marie Pédrot).The
Automatic Introduction
option has been removed and is now the default (#9001, by Emilio Jesús Gallego Arias).Arguments
now accepts names for arguments provided withextra_scopes
(#9117, by Maxime Dénès).The naming scheme for anonymous binders in a
Theorem
has changed to avoid conflicts with explicitly named binders (#9160, closes #8819, by Jasper Hugunin).Computation of implicit arguments now properly handles local definitions in the binders for an
Instance
, and can be mixed with implicit binders{x : T}
(#9307, closes #9300, by Jasper Hugunin).Declare Instance
now requires an instance name.The flag
Refine Instance Mode
has been turned off by default, meaning thatInstance
no longer opens a proof when a body is provided. The flag has been deprecated and will be removed in the next version.Command
Instance
, when no body is provided, now always opens a proof. This is a breaking change, as instance ofInstance ident1 : ident2.
whereident2
is a trivial class will have to be changed intoInstance ident1 : ident2 := {}.
orInstance ident1 : ident2. Proof. Qed.
(#9274, by Maxime Dénès).The flag
Program Mode
now means that theProgram
attribute is enabled for all commands that support it. In particular, it does not have any effect on tactics anymore. May cause some incompatibilities (#9410, by Maxime Dénès).The algorithm computing implicit arguments now behaves uniformly for primitive projection and application nodes (#9509, closes #9508, by Pierre-Marie Pédrot).
Hypotheses
andVariables
can now take implicit binders inside sections (#9364, closes #9363, by Jasper Hugunin).Removed deprecated option
Automatic Coercions Import
(#8094, by Maxime Dénès).The
Show Script
command has been deprecated (#9829, by Vincent Laporte).Coercion
does not warn ambiguous paths which are obviously convertible with existing ones. The ambiguous paths messages have been turned to warnings, thus now they could appear in the output ofcoqc
. The convertibility checking procedure for coercion paths is complete for paths consisting of coercions satisfying the uniform inheritance condition, but some coercion paths could be reported as ambiguous even if they are convertible with existing ones when they have coercions that don't satisfy the uniform inheritance condition (#9743, closes #3219, by Kazuhiko Sakaguchi).A new flag
Fast Name Printing
has been introduced. It changes the algorithm used for allocating bound variable names for a faster but less clever one (#9078, by Pierre-Marie Pédrot).Option
Typeclasses Axioms Are Instances
(compatibility option introduced in the previous version) is deprecated. UseDeclare Instance
for axioms which should be instances (#8920, by Gaëtan Gilbert).Removed option
Printing Primitive Projection Compatibility
(#9306, by Gaëtan Gilbert).
Standard Library:
Added
Bvector.BVeq
that decides whether twoBvector
s are equal. Added notations forBVxor
,BVand
,BVor
,BVeq
andBVneg
(#8171, by Yishuai Li).Added
ByteVector
type that can convert to and fromstring
(#8365, by Yishuai Li).Added lemmas about monotonicity of
N.double
andN.succ_double
, and about the upper bound of number represented by a vector. Allowed implicit vector length argument inNdigits.Bv2N
(#8815, by Yishuai Li).The prelude used to be automatically Exported and is now only Imported. This should be relevant only when importing files which don't use
-noinit
into files which do (#9013, by Gaëtan Gilbert).Added
Coq.Structures.OrderedTypeEx.String_as_OT
to make strings an ordered type, using lexical order (#7221, by Li Yao).Added lemmas about
Z.testbit
,Z.ones
, andZ.modulo
(#9425, by Andres Erbsen).Moved the
auto
hints of theFSet
library into a newfset
database (#9725, by Frédéric Besson).Added
Coq.Structures.EqualitiesFacts.PairUsualDecidableTypeFull
(#9984, by Jean-Christophe Léchenet and Oliver Nash).
Some error messages that show problems with a pair of non-matching values will now highlight the differences (#8669, by Jim Fehrle).
Changelog has been moved from a specific file
CHANGES.md
to the reference manual; former Credits chapter of the reference manual has been split in two parts: a History chapter which was enriched with additional historical information about Coq versions 1 to 5, and a Changes chapter which was enriched with the content formerly inCHANGES.md
andCOMPATIBILITY
(#9133, #9668, #9939, #9964, and #10085, by Théo Zimmermann, with help and ideas from Emilio Jesús Gallego Arias, Gaëtan Gilbert, Clément Pit-Claudel, Matthieu Sozeau, and Enrico Tassi).
Changes in 8.10+beta2¶
Many bug fixes and documentation improvements, in particular:
Tactics
Make the
discriminate
tactic work together withUniverse Polymorphism
and equality inType
. This, in particular, makesdiscriminate
compatible with the HoTT library https://github.com/HoTT/HoTT (#10205, by Andreas Lynge, review by Pierre-Marie Pédrot and Matthieu Sozeau).
SSReflect
Make the
case E: t
tactic work together withUniverse Polymorphism
and equality inType
. This makescase
compatible with the HoTT library https://github.com/HoTT/HoTT (#10302, fixes #10301, by Andreas Lynge, review by Enrico Tassi)Make the
rewrite /t
tactic work together withUniverse Polymorphism
. This makesrewrite
compatible with the HoTT library https://github.com/HoTT/HoTT (#10305, fixes #9336, by Andreas Lynge, review by Enrico Tassi)
CoqIDE
Fix CoqIDE instability on Windows after the update to gtk3 (#10360, by Michael Soegtrop, closes #9885).
Miscellaneous
Changes in 8.10+beta3¶
Kernel
Fix soundness issue with template polymorphism (#9294).
Declarations of template-polymorphic inductive types ignored the provenance of the universes they were abstracting on and did not detect if they should be greater or equal to \(\Set\) in general. Previous universes and universes introduced by the inductive definition could have constraints that prevented their instantiation with e.g. \(\Prop\), resulting in unsound instantiations later. The implemented fix only allows abstraction over universes introduced by the inductive declaration, and properly records all their constraints by making them by default only \(>= \Prop\). It is also checked that a template polymorphic inductive actually is polymorphic on at least one universe.
This prevents inductive declarations in sections to be universe polymorphic over section parameters. For a backward compatible fix, simply hoist the inductive definition out of the section. An alternative is to declare the inductive as universe-polymorphic and cumulative in a universe-polymorphic section: all universes and constraints will be properly gathered in this case. See Template polymorphism for a detailed exposition of the rules governing template-polymorphic types.
To help users incrementally fix this issue, a command line option
-no-template-check
and a global flagTemplate Check
are available to selectively disable the new check. Use at your own risk.(#9918, by Matthieu Sozeau and Maxime Dénès).
User messages
Improve the ambiguous paths warning to indicate which path is ambiguous with new one (#10336, closes #3219, by Kazuhiko Sakaguchi).
Extraction
Fix extraction to OCaml of primitive machine integers; see Primitive Integers (#10430, fixes #10361, by Vincent Laporte).
Fix a printing bug of OCaml extraction on dependent record projections, which produced improper
assert false
. This change makes the OCaml extractor internally inline record projections by default; thus the monolithic OCaml extraction (Extraction
andRecursive Extraction
) does not produce record projection constants anymore except for record projections explicitly instructed to extract, and records declared in opaque modules (#10577, fixes #7348, by Kazuhiko Sakaguchi).
Standard library
Changes in 8.10.0¶
Changes in 8.10.1¶
A few bug fixes and documentation improvements, in particular:
Kernel
Fix proof of False when using \(\SProp\) (incorrect De Bruijn handling when inferring the relevance mark of a function) (#10904, by Pierre-Marie Pédrot).
Tactics
Tactic language
CoqIDE
Extraction
Changes in 8.10.2¶
Kernel
Fixed a critical bug of template polymorphism and nonlinear universes (#11128, fixes #11039, by Gaëtan Gilbert).
Fixed an anomaly “Uncaught exception Constr.DestKO” on
Inductive
(#11052, fixes #11048, by Gaëtan Gilbert).Fixed an anomaly “not enough abstractions in fix body” (#11014, fixes #8459, by Gaëtan Gilbert).
Notations
Fixed an 8.10 regression related to the printing of coercions associated with notations (#11090, fixes #11033, by Hugo Herbelin).
CoqIDE
Fixed uneven dimensions of CoqIDE panels when window has been resized (#11070, fixes 8.10-regression #10956, by Guillaume Melquiond).
Do not include final stops in queries (#11069, fixes 8.10-regression #11058, by Guillaume Melquiond).
Infrastructure and dependencies
Version 8.9¶
Summary of changes¶
Coq version 8.9 contains the result of refinements and stabilization of features and deprecations or removals of deprecated features, cleanups of the internals of the system and API along with a few new features. This release includes many user-visible changes, including deprecations that are documented in the next subsection and new features that are documented in the reference manual. Here are the most important changes:
Kernel: mutually recursive records are now supported, by Pierre-Marie Pédrot.
Notations:
Support for autonomous grammars of terms called “custom entries”, by Hugo Herbelin (see Section Custom entries of the reference manual).
Deprecated notations of the standard library will be removed in the next version of Coq, see the next subsection for a script to ease porting, by Jason Gross and Jean-Christophe Léchenet.
Added the
Number Notation
command for registering decimal numeral notations for custom types, by Daniel de Rauglaudre, Pierre Letouzey and Jason Gross.
Tactics: Introduction tactics
intro
/intros
on a goal that is an existential variable now force a refinement of the goal into a dependent product rather than failing, by Hugo Herbelin.Decision procedures: deprecation of tactic
romega
in favor oflia
and removal offourier
, replaced bylra
which subsumes it, by Frédéric Besson, Maxime Dénès, Vincent Laporte and Laurent Théry.Proof language: focusing bracket
{
now supports named goals, e.g.[x]:{
will focus on a goal (existential variable) namedx
, by Théo Zimmermann.SSReflect: the implementation of delayed clear was simplified by Enrico Tassi: the variables are always renamed using inaccessible names when the clear switch is processed and finally cleared at the end of the intro pattern. In addition to that, the use-and-discard flag
{}
typical of rewrite rules can now be also applied to views, e.g.=> {}/v
appliesv
and then clearsv
. See Section Introduction in the context.Vernacular:
Experimental support for attributes on commands, by Vincent Laporte, as in
#[local] Lemma foo : bar.
Tactics and tactic notations now support thedeprecated
attribute.Removed deprecated commands
Arguments Scope
andImplicit Arguments
in favor ofArguments
, with the help of Jasper Hugunin.New flag
Uniform Inductive Parameters
by Jasper Hugunin to avoid repeating uniform parameters in constructor declarations.New commands
Hint Variables
andHint Constants
, by Matthieu Sozeau, for controlling the opacity status of variables and constants in hint databases. It is recommended to always use these commands after creating a hint database withCreate HintDb
.Multiple sections with the same name are now allowed, by Jasper Hugunin.
Library: additions and changes in the
VectorDef
,Ascii
, andString
libraries. Syntax notations are now available only when usingImport
of libraries and not merelyRequire
, by various contributors (source of incompatibility, see the next subsection for details).Toplevels:
coqtop
andcoqide
can now display diffs between proof steps in color, using theDiffs
option, by Jim Fehrle.Documentation: we integrated a large number of fixes to the new Sphinx documentation by various contributors, coordinated by Clément Pit-Claudel and Théo Zimmermann.
Tools: removed the
gallina
utility and the homebrewedEmacs
mode.Packaging: as in Coq 8.8.2, the Windows installer now includes many more external packages that can be individually selected for installation, by Michael Soegtrop.
Version 8.9 also comes with a bunch of smaller-scale changes and improvements regarding the different components of the system. Most important ones are documented in the next subsection file.
On the implementation side, the dev/doc/changes.md
file documents
the numerous changes to the implementation and improvements of
interfaces. The file provides guidelines on porting a plugin to the new
version and a plugin development tutorial kept in sync with Coq was
introduced by Yves Bertot http://github.com/ybertot/plugin_tutorials.
The new dev/doc/critical-bugs
file documents the known critical bugs
of Coq and affected releases.
The efficiency of the whole system has seen improvements thanks to contributions from Gaëtan Gilbert, Pierre-Marie Pédrot, and Maxime Dénès.
Maxime Dénès, Emilio Jesús Gallego Arias, Gaëtan Gilbert, Michael Soegtrop, Théo Zimmermann worked on maintaining and improving the continuous integration system.
The opam repository for Coq packages has been maintained by Guillaume Melquiond, Matthieu Sozeau, Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
The 54 contributors for this version are Léo Andrès, Rin Arakaki, Benjamin Barenblat, Langston Barrett, Siddharth Bhat, Martin Bodin, Simon Boulier, Timothy Bourke, Joachim Breitner, Tej Chajed, Arthur Charguéraud, Pierre Courtieu, Maxime Dénès, Andres Erbsen, Jim Fehrle, Julien Forest, Emilio Jesus Gallego Arias, Gaëtan Gilbert, Matěj Grabovský, Jason Gross, Samuel Gruetter, Armaël Guéneau, Hugo Herbelin, Jasper Hugunin, Ralf Jung, Sam Pablo Kuper, Ambroise Lafont, Leonidas Lampropoulos, Vincent Laporte, Peter LeFanu Lumsdaine, Pierre Letouzey, Jean-Christophe Léchenet, Nick Lewycky, Yishuai Li, Sven M. Hallberg, Assia Mahboubi, Cyprien Mangin, Guillaume Melquiond, Perry E. Metzger, Clément Pit-Claudel, Pierre-Marie Pédrot, Daniel R. Grayson, Kazuhiko Sakaguchi, Michael Soegtrop, Matthieu Sozeau, Paul Steckler, Enrico Tassi, Laurent Théry, Anton Trunov, whitequark, Théo Winterhalter, Zeimer, Beta Ziliani, Théo Zimmermann.
Many power users helped to improve the design of the new features via the issue and pull request system, the Coq development mailing list or the coq-club@inria.fr mailing list. It would be impossible to mention exhaustively the names of everybody who to some extent influenced the development.
Version 8.9 is the fourth release of Coq developed on a time-based development cycle. Its development spanned 7 months from the release of Coq 8.8. The development moved to a decentralized merging process during this cycle. Guillaume Melquiond was in charge of the release process and is the maintainer of this release. This release is the result of ~2,000 commits and ~500 PRs merged, closing 75+ issues.
The Coq development team welcomed Vincent Laporte, a new Coq engineer working with Maxime Dénès in the Coq consortium.
Details of changes in 8.9+beta1¶
Kernel
Mutually defined records are now supported.
Notations
New support for autonomous grammars of terms, called "custom entries" (see chapter "Syntax extensions" of the reference manual).
Deprecated compatibility notations will actually be removed in the next version of Coq. Uses of these notations are generally easy to fix thanks to the hint contained in the deprecation warnings. For projects that require more than a handful of such fixes, there is a script that will do it automatically, using the output of
coqc
. The script contains documentation on its usage in a comment at the top.
Tactics
Added toplevel goal selector
!
which expects a single focused goal. Use withSet Default Goal Selector
to force focusing before tactics are called.The undocumented "nameless" forms
fix N
,cofix
that were deprecated in 8.8 have been removed from Ltac's syntax; please usefix ident N/cofix ident
to explicitly name the (co)fixpoint hypothesis to be introduced.Introduction tactics
intro
/intros
on a goal that is an existential variable now force a refinement of the goal into a dependent product rather than failing.Support for
fix
/cofix
added in Ltacmatch
andlazymatch
.Ltac backtraces now include trace information about tactics called by OCaml-defined tactics.
Option
Ltac Debug
now applies also to terms built using Ltac functions.Deprecated the
Implicit Tactic
family of commands.The default program obligation tactic uses a bounded proof search instead of an unbounded and potentially non-terminating one now (source of incompatibility).
The
simple apply
tactic now respects theOpaque
flag when called from Ltac (auto
still does not respect it).Tactic
constr_eq
now adds universe constraints needed for the identity to the context (it used to ignore them). New tacticconstr_eq_strict
checks that the required constraints already hold without adding new ones. Preexisting tacticconstr_eq_nounivs
can still be used if you really want to ignore universe constraints.Tactics and tactic notations now understand the
deprecated
attribute.The
fourier
tactic has been removed. Please now uselra
instead. You may need to addRequire Import Lra
to your developments. For compatibility, we now definefourier
as a deprecated alias oflra
.The
romega
tactics have been deprecated; please uselia
instead.
Focusing
Focusing bracket
{
now supports named goal selectors, e.g.[x]: {
will focus on a goal (existential variable) namedx
. As usual, unfocus with}
once the subgoal is fully solved.
Specification language
A fix to unification (which was sensitive to the ascii name of variables) may occasionally change type inference in incompatible ways, especially regarding the inference of the return clause of
match
.
Standard Library
Added
Ascii.eqb
andString.eqb
and the=?
notation for them, and proved some lemmas about them. Note that this might cause incompatibilities if you have, e.g.,string_scope
andZ_scope
both open withstring_scope
on top, and expect=?
to refer toZ.eqb
. Solution: wrap_ =? _
in(_ =? _)%Z
(or whichever scope you want).Added
Ndigits.N2Bv_sized
, and proved some lemmas about it. DeprecatedNdigits.N2Bv_gen
.The scopes
int_scope
anduint_scope
have been renamed todec_int_scope
anddec_uint_scope
, to clash less with ssreflect and other packages. They are still delimited by%int
and%uint
.Syntax notations for
string
,ascii
,Z
,positive
,N
,R
, andint31
are no longer available merely byRequire
ing the files that define the inductives. You mustImport
Coq.Strings.String.StringSyntax
(afterRequire
Coq.Strings.String
),Coq.Strings.Ascii.AsciiSyntax
(afterRequire
Coq.Strings.Ascii
),Coq.ZArith.BinIntDef
,Coq.PArith.BinPosDef
,Coq.NArith.BinNatDef
,Coq.Reals.Rdefinitions
, andCoq.Numbers.Cyclic.Int31.Int31
, respectively, to be able to use these notations. Note that passing-compat 8.8
or issuingRequire Import Coq.Compat.Coq88
will make these notations available. Users wishing to port their developments automatically may downloadfix.py
from https://gist.github.com/JasonGross/5d4558edf8f5c2c548a3d96c17820169 and run a command likewhile true; do make -Okj 2>&1 | /path/to/fix.py; done
and get a cup of coffee. (This command must be manually interrupted once the build finishes all the way though. Note also that this method is not fail-proof; you may have to adjust some scopes if you were relying on string notations not being available even whenstring_scope
was open.)Numeral syntax for
nat
is no longer available without loading the entire prelude (Require Import Coq.Init.Prelude
). This only impacts users running Coq without the init library (-nois
or-noinit
) and also issuingRequire Import Coq.Init.Datatypes
.
Tools
Coq_makefile lets one override or extend the following variables from the command line:
COQFLAGS
,COQCHKFLAGS
,COQDOCFLAGS
.COQFLAGS
is now entirely separate fromCOQLIBS
, so in custom Makefiles$(COQFLAGS)
should be replaced by$(COQFLAGS) $(COQLIBS)
.Removed the
gallina
utility (extracts specification from Coq vernacular files). If you would like to maintain this tool externally, please contact us.Removed the Emacs modes distributed with Coq. You are advised to use Proof-General (and optionally Company-Coq) instead. If your use case is not covered by these alternative Emacs modes, please open an issue. We can help set up external maintenance as part of Proof-General, or independently as part of coq-community.
Commands
Removed deprecated commands
Arguments Scope
andImplicit Arguments
(not the option). Use theArguments
command instead.Nested proofs may be enabled through the option
Nested Proofs Allowed
. By default, they are disabled and produce an error. The deprecation warning which used to occur when using nested proofs has been removed.Added option
Uniform Inductive Parameters
which abstracts over parameters before typechecking constructors, allowing to write for exampleInductive list (A : Type) := nil : list | cons : A -> list -> list.
New
Set Hint Variables/Constants Opaque/Transparent
commands for setting globally the opacity flag of variables and constants in hint databases, overriding the opacity setting of the hint database.Added generic syntax for "attributes", as in:
#[local] Lemma foo : bar.
Added the
Numeral Notation
command for registering decimal numeral notations for custom typesThe
Set SsrHave NoTCResolution
command no longer has special global scope. If you want the previous behavior, useGlobal Set SsrHave NoTCResolution
.Multiple sections with the same name are allowed.
Coq binaries and process model
Before 8.9, Coq distributed a single
coqtop
binary and a set of dynamically loadable plugins that used to take over the main loop for tasks such as IDE language server or parallel proof checking.These plugins have been turned into full-fledged binaries so each different process has associated a particular binary now, in particular
coqidetop
is the CoqIDE language server, andcoq{proof,tactic,query}worker
are in charge of task-specific and parallel proof checking.
SSReflect
The implementation of delayed clear switches in intro patterns is now simpler to explain:
The immediate effect of a clear switch like
{x}
is to rename the variablex
to_x_
(i.e. a reserved identifier that cannot be mentioned explicitly)The delayed effect of
{x}
is that_x_
is cleared at the end of the intro patternA clear switch immediately before a view application like
{x}/v
is translated to/v{x}
.
In particular, the third rule lets one write
{x}/v
even ifv
uses the variablex
: indeed the view is executed before the renaming.An empty clear switch is now accepted in intro patterns before a view application whenever the view is a variable. One can now write
{}/v
to mean{v}/v
. Remark that{}/x
is very similar to the idiom{}e
for the rewrite tactic (the equatione
is used for rewriting and then discarded).
Standard Library
There are now conversions between
string
andpositive
,Z
,nat
, andN
in binary, octal, and hex.
Display diffs between proof steps
coqtop
andcoqide
can now highlight the differences between proof steps in color. This can be enabled from the command line or theSet Diffs "on"/"off"/"removed"
command. Please see the documentation for details. Showing diffs in Proof General requires small changes to PG (under discussion).
Notations
Added
++
infix forVectorDef.append
. Note that this might cause incompatibilities if you have, e.g.,list_scope
andvector_scope
both open withvector_scope
on top, and expect++
to refer toapp
. Solution: wrap_ ++ _
in(_ ++ _)%list
(or whichever scope you want).
Changes in 8.8.0¶
Various bug fixes.
Changes in 8.8.1¶
Some quality-of-life fixes.
Numerous improvements to the documentation.
Fix a critical bug related to primitive projections and
native_compute
.Ship several additional Coq libraries with the Windows installer.
Version 8.8¶
Summary of changes¶
Coq version 8.8 contains the result of refinements and stabilization of features and deprecations, cleanups of the internals of the system along with a few new features. The main user visible changes are:
Kernel: fix a subject reduction failure due to allowing fixpoints on non-recursive values, by Matthieu Sozeau. Handling of evars in the VM (the kernel still does not accept evars) by Pierre-Marie Pédrot.
Notations: many improvements on recursive notations and support for destructuring patterns in the syntax of notations by Hugo Herbelin.
Proof language: tacticals for profiling, timing and checking success or failure of tactics by Jason Gross. The focusing bracket
{
supports single-numbered goal selectors, e.g.2:{
, by Théo Zimmermann.Vernacular: deprecation of commands and more uniform handling of the
Local
flag, by Vincent Laporte and Maxime Dénès, part of a larger attribute system overhaul. ExperimentalShow Extraction
command by Pierre Letouzey. Coercion now acceptsProp
orType
as a source by Arthur Charguéraud.Export
modifier for options allowing to export the option to modules thatImport
and not onlyRequire
a module, by Pierre-Marie Pédrot.Universes: many user-level and API level enhancements: qualified naming and printing, variance annotations for cumulative inductive types, more general constraints and enhancements of the minimization heuristics, interaction with modules by Gaëtan Gilbert, Pierre-Marie Pédrot and Matthieu Sozeau.
Library: Decimal Numbers library by Pierre Letouzey and various small improvements.
Documentation: a large community effort resulted in the migration of the reference manual to the Sphinx documentation tool. The result is this manual. The new documentation infrastructure (based on Sphinx) is by Clément Pit-Claudel. The migration was coordinated by Maxime Dénès and Paul Steckler, with some help of Théo Zimmermann during the final integration phase. The 14 people who ported the manual are Calvin Beck, Heiko Becker, Yves Bertot, Maxime Dénès, Richard Ford, Pierre Letouzey, Assia Mahboubi, Clément Pit-Claudel, Laurence Rideau, Matthieu Sozeau, Paul Steckler, Enrico Tassi, Laurent Théry, Nikita Zyuzin.
Tools: experimental
-mangle-names
option tocoqtop
/coqc
for linting proof scripts, by Jasper Hugunin.
On the implementation side, the dev/doc/changes.md
file
documents the numerous changes to the implementation and improvements of
interfaces. The file provides guidelines on porting a plugin to the new
version.
Version 8.8 also comes with a bunch of smaller-scale changes and improvements regarding the different components of the system. Most important ones are documented in the next subsection file.
The efficiency of the whole system has seen improvements thanks to contributions from Gaëtan Gilbert, Pierre-Marie Pédrot, Maxime Dénès and Matthieu Sozeau and performance issue tracking by Jason Gross and Paul Steckler.
The official wiki and the bugtracker of Coq migrated to the GitHub platform, thanks to the work of Pierre Letouzey and Théo Zimmermann. Gaëtan Gilbert, Emilio Jesús Gallego Arias worked on maintaining and improving the continuous integration system.
The opam repository for Coq packages has been maintained by Guillaume Melquiond, Matthieu Sozeau, Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
The 44 contributors for this version are Yves Bertot, Joachim Breitner, Tej Chajed, Arthur Charguéraud, Jacques-Pascal Deplaix, Maxime Dénès, Jim Fehrle, Julien Forest, Yannick Forster, Gaëtan Gilbert, Jason Gross, Samuel Gruetter, Thomas Hebb, Hugo Herbelin, Jasper Hugunin, Emilio Jesus Gallego Arias, Ralf Jung, Johannes Kloos, Matej Košík, Robbert Krebbers, Tony Beta Lambda, Vincent Laporte, Peter LeFanu Lumsdaine, Pierre Letouzey, Farzon Lotfi, Cyprien Mangin, Guillaume Melquiond, Raphaël Monat, Carl Patenaude Poulin, Pierre-Marie Pédrot, Clément Pit-Claudel, Matthew Ryan, Matt Quinn, Sigurd Schneider, Bernhard Schommer, Michael Soegtrop, Matthieu Sozeau, Arnaud Spiwack, Paul Steckler, Enrico Tassi, Anton Trunov, Martin Vassor, Vadim Zaliva and Théo Zimmermann.
Version 8.8 is the third release of Coq developed on a time-based development cycle. Its development spanned 6 months from the release of Coq 8.7 and was based on a public roadmap. The development process was coordinated by Matthieu Sozeau. Maxime Dénès was in charge of the release process. Théo Zimmermann is the maintainer of this release.
Many power users helped to improve the design of the new features via the bug tracker, the pull request system, the Coq development mailing list or the coq-club@inria.fr mailing list. Special thanks to the users who contributed patches and intensive brain-storming and code reviews, starting with Jason Gross, Ralf Jung, Robbert Krebbers and Amin Timany. It would however be impossible to mention exhaustively the names of everybody who to some extent influenced the development.
The Coq consortium, an organization directed towards users and supporters of the system, is now running and employs Maxime Dénès. The contacts of the Coq Consortium are Yves Bertot and Maxime Dénès.
Details of changes in 8.8+beta1¶
Kernel
Support for template polymorphism for definitions was removed. May trigger more "universe inconsistency" errors in rare occasions.
Fixpoints are no longer allowed on non-recursive inductive types.
Notations
Recursive notations with the recursive pattern repeating on the right (e.g. "( x ; .. ; y ; z )") now supported.
Notations with a specific level for the leftmost nonterminal, when printing-only, are supported.
Notations can now refer to the syntactic category of patterns (as in "fun 'pat =>" or "match p with pat => ... end"). Two variants are available, depending on whether a single variable is considered as a pattern or not.
Recursive notations now support ".." patterns with several occurrences of the recursive term or binder, possibly mixing terms and binders, possibly in reverse left-to-right order.
"Locate" now working also on notations of the form "x + y" (rather than "_ + _").
Specification language
When printing clauses of a "match", clauses with same right-hand side are factorized and the last most factorized clause with no variables, if it exists, is turned into a default clause. Use "Unset Printing Allow Default Clause" do deactivate printing of a default clause. Use "Unset Printing Factorizable Match Patterns" to deactivate factorization of clauses with same right-hand side.
Tactics
On Linux, "native_compute" calls can be profiled using the "perf" utility. The command "Set NativeCompute Profiling" enables profiling, and "Set NativeCompute Profile Filename" customizes the profile filename.
The tactic "omega" is now aware of the bodies of context variables such as "x := 5 : Z" (see #1362). This could be disabled via Unset Omega UseLocalDefs.
The tactic "romega" is also aware now of the bodies of context variables.
The tactic "zify" resp. "omega with N" is now aware of N.pred.
Tactic "decide equality" now able to manage constructors which contain proofs.
Added tactics reset ltac profile, show ltac profile (and variants)
Added tactics restart_timer, finish_timing, and time_constr as an experimental way of timing Ltac's evaluation phase
Added tactic optimize_heap, analogous to the Vernacular Optimize Heap, which performs a major garbage collection and heap compaction in the OCaml run-time system.
The tactics "dtauto", "dintuition", "firstorder" now handle inductive types with let bindings in the parameters.
The tactic
dtauto
now handles some inductives such as@sigT A (fun _ => B)
as non-dependent conjunctions.A bug fixed in
rewrite H in *
andrewrite H in * |-
may cause a few rare incompatibilities (it was unintendedly recursively rewriting in the side conditions generated by H).Added tactics "assert_succeeds tac" and "assert_fails tac" to ensure properties of the execution of a tactic without keeping the effect of the execution.
vm_compute
now supports existential variables.Calls to
shelve
andgive_up
within calls to tacticrefine
now working.Deprecated tactic
appcontext
was removed.
Focusing
Focusing bracket
{
now supports single-numbered goal selector, e.g.2: {
will focus on the second subgoal. As usual, unfocus with}
once the subgoal is fully solved. TheFocus
andUnfocus
commands are now deprecated.
Commands
Proofs ending in "Qed exporting ident, .., ident" are not supported anymore. Constants generated during
abstract
are kept private to the local environment.The deprecated Coercion Local, Open Local Scope, Notation Local syntax was removed. Use Local as a prefix instead.
For the Extraction Language command, "OCaml" is spelled correctly. The older "Ocaml" is still accepted, but deprecated.
Using “Require” inside a section is deprecated.
An experimental command "Show Extraction" allows to extract the content of the current ongoing proof (grant wish #4129).
Coercion now accepts the type of its argument to be "Prop" or "Type".
The "Export" modifier can now be used when setting and unsetting options, and will result in performing the same change when the module corresponding the command is imported.
The
Axiom
command does not automatically declare axioms as instances when their type is a class. Previous behavior can be restored usingSet Typeclasses Axioms Are Instances
.
Universes
Qualified naming of global universes now works like other namespaced objects (e.g. constants), with a separate namespace, inside and across module and library boundaries. Global universe names introduced in an inductive / constant / Let declaration get qualified with the name of the declaration.
Universe cumulativity for inductive types is now specified as a variance for each polymorphic universe. See the reference manual for more information.
Inference of universe constraints with cumulative inductive types produces more general constraints. Unsetting new option Cumulativity Weak Constraints produces even more general constraints (but may produce too many universes to be practical).
Fix #5726: Notations that start with
Type
now support universe instances with@{u}
.with Definition
now understands universe declarations (like@{u| Set < u}
).
Tools
Coq can now be run with the option -mangle-names to change the auto-generated name scheme. This is intended to function as a linter for developments that want to be robust to changes in auto-generated names. This feature is experimental, and may change or disappear without warning.
GeoProof support was removed.
Checker
The checker now accepts filenames in addition to logical paths.
CoqIDE
Find and Replace All report the number of occurrences found; Find indicates when it wraps.
coqdep
Learned to read -I, -Q, -R and filenames from _CoqProject files. This is used by coq_makefile when generating dependencies for .v files (but not other files).
Documentation
The Coq FAQ, formerly located at https://coq.inria.fr/faq, has been moved to the GitHub wiki section of this repository; the main entry page is https://github.com/coq/coq/wiki/The-Coq-FAQ.
Documentation: a large community effort resulted in the migration of the reference manual to the Sphinx documentation tool. The result is partially integrated in this version.
Standard Library
New libraries Coq.Init.Decimal, Coq.Numbers.DecimalFacts, Coq.Numbers.DecimalNat, Coq.Numbers.DecimalPos, Coq.Numbers.DecimalN, Coq.Numbers.DecimalZ, Coq.Numbers.DecimalString providing a type of decimal numbers, some facts about them, and conversions between decimal numbers and nat, positive, N, Z, and string.
Added [Coq.Strings.String.concat] to concatenate a list of strings inserting a separator between each item
Notation
'
for Zpos in QArith was removed.Some deprecated aliases are now emitting warnings when used.
Compatibility support
Support for compatibility with versions before 8.6 was dropped.
Options
The following deprecated options have been removed:
Refolding Reduction
Standard Proposition Elimination
Dependent Propositions Elimination
Discriminate Introduction
Shrink Abstract
Tactic Pattern Unification
Intuition Iff Unfolding
Injection L2R Pattern Order
Record Elimination Schemes
Match Strict
Tactic Compat Context
Typeclasses Legacy Resolution
Typeclasses Module Eta
Typeclass Resolution After Apply
Details of changes in 8.8.0¶
Tools
Asynchronous proof delegation policy was fixed. Since version 8.7 Coq was ignoring previous runs and the
-async-proofs-delegation-threshold
option did not have the expected behavior.
Tactic language
The undocumented "nameless" forms
fix N
,cofix
have been deprecated; please usefix ident N /cofix ident
to explicitly name the (co)fixpoint hypothesis to be introduced.
Documentation
The reference manual is now fully ported to Sphinx.
Other small deprecations and bug fixes.
Details of changes in 8.8.1¶
Kernel
Fix a critical bug with cofixpoints and
vm_compute
/native_compute
(#7333).Fix a critical bug with modules and algebraic universes (#7695)
Fix a critical bug with inlining of polymorphic constants (#7615).
Fix a critical bug with universe polymorphism and
vm_compute
(#7723). Was present since 8.5.
Notations
Fixed unexpected collision between only-parsing and only-printing notations (issue #7462).
Windows installer
The Windows installer now includes external packages Ltac2 and Equations (it included the Bignums package since 8.8+beta1).
Many other bug fixes, documentation improvements (including fixes of regressions due to the Sphinx migration), and user message improvements (for details, see the 8.8.1 milestone at https://github.com/coq/coq/milestone/13?closed=1).
Details of changes in 8.8.2¶
Documentation
A PDF version of the reference manual is available once again.
Tools
The coq-makefile targets
print-pretty-timed
,print-pretty-timed-diff
, andprint-pretty-single-time-diff
now correctly label the "before" and "after" columns, rather than swapping them.
Kernel
The kernel does not tolerate capture of global universes by polymorphic universe binders, fixing a soundness break (triggered only through custom plugins)
Windows installer
The Windows installer now includes many more external packages that can be individually selected for installation.
Many other bug fixes and lots of documentation improvements (for details, see the 8.8.2 milestone at https://github.com/coq/coq/milestone/15?closed=1).
Version 8.7¶
Summary of changes¶
Coq version 8.7 contains the result of refinements, stabilization of features and cleanups of the internals of the system along with a few new features. The main user visible changes are:
New tactics: variants of tactics supporting existential variables
eassert
,eenough
, etc... by Hugo Herbelin. Tacticsextensionality in H
andinversion_sigma
by Jason Gross,specialize with ...
accepting partial bindings by Pierre Courtieu.Cumulative Polymorphic Inductive
types, allowing cumulativity of universes to go through applied inductive types, by Amin Timany and Matthieu Sozeau.Integration of the SSReflect plugin and its documentation in the reference manual, by Enrico Tassi, Assia Mahboubi and Maxime Dénès.
The
coq_makefile
tool was completely redesigned to improve its maintainability and the extensibility of generated Makefiles, and to make_CoqProject
files more palatable to IDEs by Enrico Tassi.
Coq 8.7 involved a large amount of work on cleaning and speeding up the code
base, notably the work of Pierre-Marie Pédrot on making the tactic-level system
insensitive to existential variable expansion, providing a safer API to plugin
writers and making the code more robust. The dev/doc/changes.txt
file
documents the numerous changes to the implementation and improvements of
interfaces. An effort to provide an official, streamlined API to plugin writers
is in progress, thanks to the work of Matej Košík.
Version 8.7 also comes with a bunch of smaller-scale changes and improvements regarding the different components of the system. We shall only list a few of them.
The efficiency of the whole system has been significantly improved thanks to contributions from Pierre-Marie Pédrot, Maxime Dénès and Matthieu Sozeau and performance issue tracking by Jason Gross and Paul Steckler.
Thomas Sibut-Pinote and Hugo Herbelin added support for side effect hooks in cbv, cbn and simpl. The side effects are provided via a plugin available at https://github.com/herbelin/reduction-effects/.
The BigN, BigZ, BigQ libraries are no longer part of the Coq standard library, they are now provided by a separate repository https://github.com/coq/bignums, maintained by Pierre Letouzey.
In the Reals library, IZR
has been changed to produce a compact representation
of integers and real constants are now represented using IZR
(work by
Guillaume Melquiond).
Standard library additions and improvements by Jason Gross, Pierre Letouzey and others, documented in the next subsection file.
The mathematical proof language/declarative mode plugin was removed from the archive.
The opam repository for Coq packages has been maintained by Guillaume Melquiond, Matthieu Sozeau, Enrico Tassi with contributions from many users. A list of packages is available at https://coq.inria.fr/opam/www/.
Packaging tools and software development kits were prepared by Michael Soegtrop with the help of Maxime Dénès and Enrico Tassi for Windows, and Maxime Dénès for MacOS X. Packages are regularly built on the Travis continuous integration server.
The contributors for this version are Abhishek Anand, C.J. Bell, Yves Bertot, Frédéric Besson, Tej Chajed, Pierre Courtieu, Maxime Dénès, Julien Forest, Gaëtan Gilbert, Jason Gross, Hugo Herbelin, Emilio Jesús Gallego Arias, Ralf Jung, Matej Košík, Xavier Leroy, Pierre Letouzey, Assia Mahboubi, Cyprien Mangin, Erik Martin-Dorel, Olivier Marty, Guillaume Melquiond, Sam Pablo Kuper, Benjamin Pierce, Pierre-Marie Pédrot, Lars Rasmusson, Lionel Rieg, Valentin Robert, Yann Régis-Gianas, Thomas Sibut-Pinote, Michael Soegtrop, Matthieu Sozeau, Arnaud Spiwack, Paul Steckler, George Stelle, Pierre-Yves Strub, Enrico Tassi, Hendrik Tews, Amin Timany, Laurent Théry, Vadim Zaliva and Théo Zimmermann.
The development process was coordinated by Matthieu Sozeau with the help of Maxime Dénès, who was also in charge of the release process. Théo Zimmermann is the maintainer of this release.
Many power users helped to improve the design of the new features via the bug tracker, the pull request system, the Coq development mailing list or the Coq-Club mailing list. Special thanks to the users who contributed patches and intensive brain-storming and code reviews, starting with Jason Gross, Ralf Jung, Robbert Krebbers, Xavier Leroy, Clément Pit–Claudel and Gabriel Scherer. It would however be impossible to mention exhaustively the names of everybody who to some extent influenced the development.
Version 8.7 is the second release of Coq developed on a time-based development cycle. Its development spanned 9 months from the release of Coq 8.6 and was based on a public road-map. It attracted many external contributions. Code reviews and continuous integration testing were systematically used before integration of new features, with an important focus given to compatibility and performance issues, resulting in a hopefully more robust release than Coq 8.6 while maintaining compatibility.
Coq Enhancement Proposals (CEPs for short) and open pull request discussions were used to discuss publicly the new features.
The Coq consortium, an organization directed towards users and supporters of the system, is now upcoming and will rely on Inria’s newly created Foundation.
Potential compatibility issues¶
Extra superfluous names in introduction patterns may now raise an error rather than a warning when the superfluous name is already in use. The easy fix is to remove the superfluous name.
Details of changes in 8.7+beta1¶
Tactics
New tactic "extensionality in H" which applies (possibly dependent) functional extensionality in H supposed to be a quantified equality until giving a bare equality.
New tactic
inversion_sigma
which turns equalities of dependent pairs (e.g.,existT P x p = existT P y q
, frequently left over byinversion
on a dependent type family) into pairs of equalities (e.g., a hypothesisH : x = y
and a hypothesis of typerew H in p = q
); these hypotheses can subsequently be simplified usingsubst
, without ever invoking any kind of axiom asserting uniqueness of identity proofs. If you want to explicitly specify the hypothesis to be inverted, or name the generated hypotheses, you can invokeinduction H as [H1 H2] using eq_sigT_rect
. The tactic also works forsig
,sigT2
, andsig2
, and there are similareq_sig*_rect
induction lemmas.Tactic "specialize with ..." now accepts any partial bindings. Missing bindings are either solved by unification or left quantified in the hypothesis.
New representation of terms that statically ensure stability by evar-expansion. This has several consequences.
In terms of performance, this adds a cost to every term destructuration, but at the same time most eager evar normalizations were removed, which couterbalances this drawback and even sometimes outperforms the old implementation. For instance, many operations that would require O(n) normalization of the term are now O(1) in tactics. YMMV.
This triggers small changes in unification, which was not evar-insensitive. Most notably, the new implementation recognizes Miller patterns that were missed before because of a missing normalization step. Hopefully this should be fairly uncommon.
Tactic "auto with real" can now discharge comparisons of literals.
The types of variables in patterns of "match" are now beta-iota-reduced after type checking. This has an impact on the type of the variables that the tactic "refine" introduces in the context, producing types that should be closer to the expectations.
In "Tactic Notation" or "TACTIC EXTEND", entry "constr_with_bindings" now uses type classes and rejects terms with unresolved holes, like entry "constr" does. To get the former behavior use "open_constr_with_bindings" (possible source of incompatibility).
New e-variants eassert, eenough, epose proof, eset, eremember, epose which behave like the corresponding variants with no "e" but turn unresolved implicit arguments into existential variables, on the shelf, rather than failing.
Tactic injection has become more powerful (closes bug #4890) and its documentation has been updated.
New variants of the
first
andsolve
tacticals that do not rely on parsing rules, meant to define tactic notations.Added support for side effects hooks in
cbv
,cbn
andsimpl
. The side effects are provided via a plugin: https://github.com/herbelin/reduction-effects/It is now possible to take hint database names as parameters in a Ltac definition or a Tactic Notation.
New option
Set Ltac Batch Debug
on top ofSet Ltac Debug
for non-interactive Ltac debug output.
Gallina
Now supporting all kinds of binders, including 'pat, in syntax of record fields.
Commands
Goals context can be printed in a more compact way when
Set Printing Compact Contexts
is activated.Unfocused goals can be printed with the
Set Printing Unfocused
option.Print
now shows the types of let-bindings.The compatibility options for printing primitive projections (
Set Printing Primitive Projection Parameters
andSet Printing Primitive Projection Compatibility
) are now off by default.Possibility to unset the printing of notations in a more fine grained fashion than
Unset Printing Notations
is provided without any user-syntax. The goal is that someone creates a plugin to experiment such a user-syntax, to be later integrated in Coq when stabilized.About
now tells if a reference is a coercion.The deprecated
Save
vernacular and its formSave Theorem id
to close proofs have been removed from the syntax. Please useQed
.Search
now sorts results by relevance (the relevance metric is a weighted sum of number of distinct symbols and size of the term).
Standard Library
New file PropExtensionality.v to explicitly work in the axiomatic context of propositional extensionality.
New file SetoidChoice.v axiomatically providing choice over setoids, and, consequently, choice of representatives in equivalence classes. Various proof-theoretic characterizations of choice over setoids in file ChoiceFacts.v.
New lemmas about iff and about orders on positive and Z.
New lemmas on powerRZ.
Strengthened statement of JMeq_eq_dep (closes bug #4912).
The BigN, BigZ, BigZ libraries are no longer part of the Coq standard library, they are now provided by a separate repository https://github.com/coq/bignums The split has been done just after the Int31 library.
IZR (Reals) has been changed to produce a compact representation of integers. As a consequence, IZR is no longer convertible to INR and lemmas such as INR_IZR_INZ should be used instead.
Real constants are now represented using IZR rather than R0 and R1; this might cause rewriting rules to fail to apply to constants.
Added new notation {x & P} for sigT (without a type for x)
Plugins
The Ssreflect plugin is now distributed with Coq. Its documentation has been integrated as a chapter of the reference manual. This chapter is work in progress so feedback is welcome.
The mathematical proof language (also known as declarative mode) was removed.
A new command Extraction TestCompile has been introduced, not meant for the general user but instead for Coq's test-suite.
The extraction plugin is no longer loaded by default. It must be explicitly loaded with [Require Extraction], which is backwards compatible.
The functional induction plugin (which provides the [Function] vernacular) is no longer loaded by default. It must be explicitly loaded with [Require FunInd], which is backwards compatible.
Dependencies
Support for camlp4 has been removed.
Tools
coq_makefile was completely redesigned to improve its maintainability and the extensibility of generated Makefiles, and to make _CoqProject files more palatable to IDEs. Overview:
_CoqProject files contain only Coq specific data (i.e. the list of files, -R options, ...)
coq_makefile translates _CoqProject to Makefile.conf and copies in the desired location a standard Makefile (that reads Makefile.conf)
Makefile extensions can be implemented in a Makefile.local file (read by the main Makefile) by installing a hook in the extension points provided by the standard Makefile
The current version contains code for retro compatibility that prints warnings when a deprecated feature is used. Please upgrade your _CoqProject accordingly.
Additionally, coq_makefile-made Makefiles now support experimental timing targets
pretty-timed
,pretty-timed-before
,pretty-timed-after
,print-pretty-timed-diff
,print-pretty-single-time-diff
,all.timing.diff
, and the variableTIMING=1
(orTIMING=before
orTIMING=after
); see the documentation for more details.
Build Infrastructure
Note that 'make world' does not build the bytecode binaries anymore. For that, you can use 'make byte' (and 'make install-byte' afterwards). Warning: native and byte compilations should not be mixed in the same instance of 'make -j', otherwise both ocamlc and ocamlopt might race for access to the same .cmi files. In short, use "make -j && make -j byte" instead of "make -j world byte".
Universes
Cumulative inductive types. see prefixes "Cumulative", "NonCumulative" for inductive definitions and the option "Set Polymorphic Inductive Cumulativity" in the reference manual.
New syntax
foo@{_}
to instantiate a polymorphic definition with anonymous universes (can also be used withType
).
XML Protocol and internal changes
See dev/doc/changes.txt
Many bugfixes including #1859, #2884, #3613, #3943, #3994, #4250, #4709, #4720, #4824, #4844, #4911, #5026, #5233, #5275, #5315, #5336, #5360, #5390, #5414, #5417, #5420, #5439, #5449, #5475, #5476, #5482, #5501, #5507, #5520, #5523, #5524, #5553, #5577, #5578, #5589, #5597, #5598, #5607, #5618, #5619, #5620, #5641, #5648, #5651, #5671.
Many bugfixes on OS X and Windows (now the test-suite passes on these platforms too).
Many optimizations.
Many documentation improvements.
Details of changes in 8.7+beta2¶
Tools
In CoqIDE, the "Compile Buffer" command takes account of flags in _CoqProject or other project file.
Improvements around some error messages.
Many bug fixes including two important ones:
Bug #5730: CoqIDE becomes unresponsive on file open.
coq_makefile: make sure compile flags for Coq and coq_makefile are in sync (in particular, make sure the
-safe-string
option is used to compile plugins).
Details of changes in 8.7.0¶
OCaml
Users can pass specific flags to the OCaml optimizing compiler by -using the flambda-opts configure-time option.
Beware that compiling Coq with a flambda-enabled compiler is experimental and may require large amounts of RAM and CPU, see INSTALL for more details.
Details of changes in 8.7.1¶
Compatibility with OCaml 4.06.0.
Many bug fixes, documentation improvements, and user message improvements (for details see the 8.7.1 milestone at https://github.com/coq/coq/milestone/10?closed=1).
Details of changes in 8.7.2¶
Fixed a critical bug in the VM handling of universes (#6677). This bug affected all releases since 8.5.
Improved support for building with OCaml 4.06.0 and external num package.
Many other bug fixes, documentation improvements, and user message improvements (for details, see the 8.7.2 milestone at https://github.com/coq/coq/milestone/11?closed=1).
Version 8.6¶
Summary of changes¶
Coq version 8.6 contains the result of refinements, stabilization of 8.5’s features and cleanups of the internals of the system. Over the year of (now time-based) development, about 450 bugs were resolved and over 100 contributions integrated. The main user visible changes are:
A new, faster state-of-the-art universe constraint checker, by Jacques-Henri Jourdan.
In CoqIDE and other asynchronous interfaces, more fine-grained asynchronous processing and error reporting by Enrico Tassi, making Coq capable of recovering from errors and continue processing the document.
More access to the proof engine features from Ltac: goal management primitives, range selectors and a
typeclasses eauto
engine handling multiple goals and multiple successes, by Cyprien Mangin, Matthieu Sozeau and Arnaud Spiwack.Tactic behavior uniformization and specification, generalization of intro-patterns by Hugo Herbelin and others.
A brand new warning system allowing to control warnings, turn them into errors or ignore them selectively by Maxime Dénès, Guillaume Melquiond, Pierre-Marie Pédrot and others.
Irrefutable patterns in abstractions, by Daniel de Rauglaudre.
The ssreflect subterm selection algorithm by Georges Gonthier and Enrico Tassi is now accessible to tactic writers through the ssrmatching plugin.
Integration of LtacProf, a profiler for Ltac by Jason Gross, Paul Steckler, Enrico Tassi and Tobias Tebbi.
Coq 8.6 also comes with a bunch of smaller-scale changes and improvements regarding the different components of the system. We shall only list a few of them.
The iota reduction flag is now a shorthand for match, fix and cofix flags controlling the corresponding reduction rules (by Hugo Herbelin and Maxime Dénès).
Maxime Dénès maintained the native compilation machinery.
Pierre-Marie Pédrot separated the Ltac code from general purpose tactics, and generalized and rationalized the handling of generic arguments, allowing to create new versions of Ltac more easily in the future.
In patterns and terms, @, abbreviations and notations are now interpreted the same way, by Hugo Herbelin.
Name handling for universes has been improved by Pierre-Marie Pédrot and Matthieu Sozeau. The minimization algorithm has been improved by Matthieu Sozeau.
The unifier has been improved by Hugo Herbelin and Matthieu Sozeau, fixing some incompatibilities introduced in Coq 8.5. Unification constraints can now be left floating around and be seen by the user thanks to a new option. The Keyed Unification mode has been improved by Matthieu Sozeau.
The typeclass resolution engine and associated proof search tactic have been reimplemented on top of the proof-engine monad, providing better integration in tactics, and new options have been introduced to control it, by Matthieu Sozeau with help from Théo Zimmermann.
The efficiency of the whole system has been significantly improved thanks to contributions from Pierre-Marie Pédrot, Maxime Dénès and Matthieu Sozeau and performance issue tracking by Jason Gross and Paul Steckler.
Standard library improvements by Jason Gross, Sébastien Hinderer, Pierre Letouzey and others.
Emilio Jesús Gallego Arias contributed many cleanups and refactorings of the pretty-printing and user interface communication components.
Frédéric Besson maintained the micromega tactic.
The opam repository for Coq packages has been maintained by Guillaume Claret, Guillaume Melquiond, Matthieu Sozeau, Enrico Tassi and others. A list of packages is now available at https://coq.inria.fr/opam/www/.
Packaging tools and software development kits were prepared by Michael Soegtrop with the help of Maxime Dénès and Enrico Tassi for Windows, and Maxime Dénès and Matthieu Sozeau for MacOS X. Packages are now regularly built on the continuous integration server. Coq now comes with a META file usable with ocamlfind, contributed by Emilio Jesús Gallego Arias, Gregory Malecha, and Matthieu Sozeau.
Matej Košík maintained and greatly improved the continuous integration setup and the testing of Coq contributions. He also contributed many API improvements and code cleanups throughout the system.
The contributors for this version are Bruno Barras, C.J. Bell, Yves Bertot, Frédéric Besson, Pierre Boutillier, Tej Chajed, Guillaume Claret, Xavier Clerc, Pierre Corbineau, Pierre Courtieu, Maxime Dénès, Ricky Elrod, Emilio Jesús Gallego Arias, Jason Gross, Hugo Herbelin, Sébastien Hinderer, Jacques-Henri Jourdan, Matej Košík, Xavier Leroy, Pierre Letouzey, Gregory Malecha, Cyprien Mangin, Erik Martin-Dorel, Guillaume Melquiond, Clément Pit–Claudel, Pierre-Marie Pédrot, Daniel de Rauglaudre, Lionel Rieg, Gabriel Scherer, Thomas Sibut-Pinote, Matthieu Sozeau, Arnaud Spiwack, Paul Steckler, Enrico Tassi, Laurent Théry, Nickolai Zeldovich and Théo Zimmermann. The development process was coordinated by Hugo Herbelin and Matthieu Sozeau with the help of Maxime Dénès, who was also in charge of the release process.
Many power users helped to improve the design of the new features via the bug tracker, the pull request system, the Coq development mailing list or the Coq-Club mailing list. Special thanks to the users who contributed patches and intensive brain-storming and code reviews, starting with Cyril Cohen, Jason Gross, Robbert Krebbers, Jonathan Leivent, Xavier Leroy, Gregory Malecha, Clément Pit–Claudel, Gabriel Scherer and Beta Ziliani. It would however be impossible to mention exhaustively the names of everybody who to some extent influenced the development.
Version 8.6 is the first release of Coq developed on a time-based development cycle. Its development spanned 10 months from the release of Coq 8.5 and was based on a public roadmap. To date, it contains more external contributions than any previous Coq system. Code reviews were systematically done before integration of new features, with an important focus given to compatibility and performance issues, resulting in a hopefully more robust release than Coq 8.5.
Coq Enhancement Proposals (CEPs for short) were introduced by Enrico Tassi to provide more visibility and a discussion period on new features, they are publicly available https://github.com/coq/ceps.
Started during this period, an effort is led by Yves Bertot and Maxime Dénès to put together a Coq consortium.
Potential sources of incompatibilities¶
Symptom: An obligation generated by Program or an abstracted subproof has different arguments.
Cause: Set Shrink Abstract and Set Shrink Obligations are on by default and the subproof does not use the argument.
Remedy:
Adapt the script.
Write an explicit lemma to prove the obligation/subproof and use it instead (compatible with 8.4).
Unset the option for the program/proof the obligation/subproof originates from.
Symptom: In a goal, order of hypotheses, or absence of an equality of the form "x = t" or "t = x", or no unfolding of a local definition.
Cause: This might be connected to a number of fixes in the tactic "subst". The former behavior can be reactivated by issuing "Unset Regular Subst Tactic".
Details of changes in 8.6beta1¶
Kernel
A new, faster state-of-the-art universe constraint checker.
Specification language
Giving implicit arguments explicitly to a constant with multiple choices of implicit arguments does not break any more insertion of further maximal implicit arguments.
Ability to put any pattern in binders, prefixed by quote, e.g. "fun '(a,b) => ...", "λ '(a,(b,c)), ...", "Definition foo '(x,y) := ...". It expands into a "let 'pattern := ..."
Tactics
Flag "Bracketing Last Introduction Pattern" is now on by default.
Flag "Regular Subst Tactic" is now on by default: it respects the initial order of hypothesis, it contracts cycles, it unfolds no local definitions (common source of incompatibilities, fixable by "Unset Regular Subst Tactic").
New flag "Refolding Reduction", now disabled by default, which turns on refolding of constants/fixpoints (as in cbn) during the reductions done during type inference and tactic retyping. Can be extremely expensive. When set off, this recovers the 8.4 behavior of unification and type inference. Potential source of incompatibility with 8.5 developments (the option is set on in Compat/Coq85.v).
New flag "Shrink Abstract" that minimalizes proofs generated by the abstract tactical w.r.t. variables appearing in the body of the proof. On by default and deprecated. Minor source of incompatibility for code relying on the precise arguments of abstracted proofs.
Serious bugs are fixed in tactic "double induction" (source of incompatibilities as soon as the inductive types have dependencies in the type of their constructors; "double induction" remains however deprecated).
In introduction patterns of the form (pat1,...,patn), n should match the exact number of hypotheses introduced (except for local definitions for which pattern can be omitted, as in regular pattern-matching).
Tactic scopes in Ltac like constr: and ltac: now require parentheses around their argument.
Every generic argument type declares a tactic scope of the form "name:(...)" where name is the name of the argument. This generalizes the constr: and ltac: instances.
When in strict mode (i.e. in a Ltac definition), if the "intro" tactic is given a free identifier, it is not bound in subsequent tactics anymore. In order to introduce a binding, use e.g. the "fresh" primitive instead (potential source of incompatibilities).
New tactics is_ind, is_const, is_proj, is_constructor for use in Ltac.
New goal selectors. Sets of goals can be selected by listing integers ranges. Example: "1,4-7,24: tac" focuses "tac" on goals 1,4,5,6,7,24.
For uniformity with "destruct"/"induction" and for a more natural behavior, "injection" can now work in place by activating option "Structural Injection". In this case, hypotheses are also put in the context in the natural left-to-right order and the hypothesis on which injection applies is cleared.
Tactic "contradiction" (hence "easy") now also solve goals with hypotheses of the form "~True" or "t<>t" (possible source of incompatibilities because of more successes in automation, but generally a more intuitive strategy).
Option "Injection On Proofs" was renamed "Keep Proof Equalities". When enabled, injection and inversion do not drop equalities between objects in Prop. Still disabled by default.
New tactics "notypeclasses refine" and "simple notypeclasses refine" that disallow typeclass resolution when typechecking their argument, for use in typeclass hints.
Integration of LtacProf, a profiler for Ltac.
Reduction tactics now accept more fine-grained flags: iota is now a shorthand for the new flags match, fix and cofix.
The ssreflect subterm selection algorithm is now accessible to tactic writers through the ssrmatching plugin.
When used as an argument of an ltac function, "auto" without "with" nor "using" clause now correctly uses only the core hint database by default.
Hints
Revised the syntax of [Hint Cut] to follow standard notation for regexps.
Hint Mode now accepts "!" which means that the mode matches only if the argument's head is not an evar (it goes under applications, casts, and scrutinees of matches and projections).
Hints can now take an optional user-given pattern, used only by [typeclasses eauto] with the [Filtered Unification] option on.
Typeclasses
Many new options and new engine based on the proof monad. The [typeclasses eauto] tactic is now a multi-goal, multi-success tactic. See reference manual for more information. It is planned to replace auto and eauto in the following version. The 8.5 resolution engine is still available to help solve compatibility issues.
Program
The "Shrink Obligations" flag now applies to all obligations, not only those solved by the automatic tactic.
"Shrink Obligations" is on by default and deprecated. Minor source of incompatibility for code relying on the precise arguments of obligations.
Notations
"Bind Scope" can once again bind "Funclass" and "Sortclass".
General infrastructure
New configurable warning system which can be controlled with the vernacular command "Set Warnings", or, under coqc/coqtop, with the flag "-w". In particular, the default is now that warnings are printed by coqc.
In asynchronous mode, Coq is now capable of recovering from errors and continue processing the document.
Tools
coqc accepts a -o option to specify the output file name
coqtop accepts --print-version to print Coq and OCaml versions in easy to parse format
Setting [Printing Dependent Evars Line] can be unset to disable the computation associated with printing the "dependent evars: " line in -emacs mode
Removed the -verbose-compat-notations flag and the corresponding Set Verbose Compat vernacular, since these warnings can now be silenced or turned into errors using "-w".
XML protocol
message format has changed, see dev/doc/changes.txt for more details.
Many bug fixes, minor changes and documentation improvements are not mentioned here.
Details of changes in 8.6¶
Kernel
Fixed critical bug #5248 in VM long multiplication on 32-bit architectures. Was there only since 8.6beta1, so no stable release impacted.
Other bug fixes in universes, type class shelving,...
Details of changes in 8.6.1¶
Fix #5380: Default colors for CoqIDE are actually applied.
Fix plugin warnings
Document named evars (including Show ident)
Fix Bug #5574, document function scope
Adding a test case as requested in bug 5205.
Fix Bug #5568, no dup notation warnings on repeated module imports
Fix documentation of Typeclasses eauto :=
Refactor documentation of records.
Protecting from warnings while compiling 8.6
Fixing an inconsistency between configure and configure.ml
Add test-suite checks for coqchk with constraints
Fix bug #5019 (looping zify on dependent types)
Fix bug 5550: "typeclasses eauto with" does not work with section variables.
Bug 5546, qualify datatype constructors when needed in Show Match
Bug #5535, test for Show with -emacs
Fix bug #5486, don't reverse ids in tuples
Fixing #5522 (anomaly with free vars of pat)
Fix bug #5526, don't check for nonlinearity in notation if printing only
Fix bug #5255
Fix bug #3659: -time should understand multibyte encodings.
FIx bug #5300: Anomaly: Uncaught exception Not_found" in "Print Assumptions".
Fix outdated description in RefMan.
Repairing
Set Rewriting Schemes
Fixing #5487 (v8.5 regression on ltac-matching expressions with evars).
Fix description of command-line arguments for Add (Rec) LoadPath
Fix bug #5377: @? patterns broken.
add XML protocol doc
Fix anomaly when doing [all:Check _.] during a proof.
Correction of bug #4306
Fix #5435: [Eval native_compute in] raises anomaly.
Instances should obey universe binders even when defined by tactics.
Intern names bound in match patterns
funind: Ignore missing info for current function
Do not typecheck twice the type of opaque constants.
show unused intro pattern warning
[future] Be eager when "chaining" already resolved future values.
Opaque side effects
Fix #5132: coq_makefile generates incorrect install goal
Run non-tactic comands without resilient_command
Univs: fix bug #5365, generation of u+k <= v constraints
make
emit
tail recursiveDon't require printing-only notation to be productive
Fix the way setoid_rewrite handles bindings.
Fix for bug 5244 - set printing width ignored when given enough space
Fix bug 4969, autoapply was not tagging shelved subgoals correctly
Version 8.5¶
Summary of changes¶
Coq version 8.5 contains the result of five specific long-term projects:
A new asynchronous evaluation and compilation mode by Enrico Tassi with help from Bruno Barras and Carst Tankink.
Full integration of the new proof engine by Arnaud Spiwack helped by Pierre-Marie Pédrot,
Addition of conversion and reduction based on native compilation by Maxime Dénès and Benjamin Grégoire.
Full universe polymorphism for definitions and inductive types by Matthieu Sozeau.
An implementation of primitive projections with η-conversion bringing significant performance improvements when using records by Matthieu Sozeau.
The full integration of the proof engine, by Arnaud Spiwack and Pierre-Marie Pédrot, brings to primitive tactics and the user level Ltac language dependent subgoals, deep backtracking and multiple goal handling, along with miscellaneous features and an improved potential for future modifications. Dependent subgoals allow statements in a goal to mention the proof of another. Proofs of unsolved subgoals appear as existential variables. Primitive backtracking makes it possible to write a tactic with several possible outcomes which are tried successively when subsequent tactics fail. Primitives are also available to control the backtracking behavior of tactics. Multiple goal handling paves the way for smarter automation tactics. It is currently used for simple goal manipulation such as goal reordering.
The way Coq processes a document in batch and interactive mode has been
redesigned by Enrico Tassi with help from Bruno Barras. Opaque proofs,
the text between Proof and Qed, can be processed asynchronously,
decoupling the checking of definitions and statements from the checking
of proofs. It improves the responsiveness of interactive development,
since proofs can be processed in the background. Similarly, compilation
of a file can be split into two phases: the first one checking only
definitions and statements and the second one checking proofs. A file
resulting from the first phase – with the .vio extension – can be
already Required. All .vio files can be turned into complete .vo files
in parallel. The same infrastructure also allows terminating tactics to
be run in parallel on a set of goals via the par:
goal selector.
CoqIDE was modified to cope with asynchronous checking of the document. Its source code was also made separate from that of Coq, so that CoqIDE no longer has a special status among user interfaces, paving the way for decoupling its release cycle from that of Coq in the future.
Carst Tankink developed a Coq back-end for user interfaces built on Makarius Wenzel’s Prover IDE framework (PIDE), like PIDE/jEdit (with help from Makarius Wenzel) or PIDE/Coqoon (with help from Alexander Faithfull and Jesper Bengtson). The development of such features was funded by the Paral-ITP French ANR project.
The full universe polymorphism extension was designed by Matthieu Sozeau. It conservatively extends the universes system and core calculus with definitions and inductive declarations parameterized by universes and constraints. It is based on a modification of the kernel architecture to handle constraint checking only, leaving the generation of constraints to the refinement/type inference engine. Accordingly, tactics are now fully universe aware, resulting in more localized error messages in case of inconsistencies and allowing higher-level algorithms like unification to be entirely type safe. The internal representation of universes has been modified but this is invisible to the user.
The underlying logic has been extended with η-conversion for records defined with primitive projections by Matthieu Sozeau. This additional form of η-conversion is justified using the same principle than the previously added η-conversion for function types, based on formulations of the Calculus of Inductive Constructions with typed equality. Primitive projections, which do not carry the parameters of the record and are rigid name