CString.Pred
type elt = t
The type of the elements in the set.
val empty : t
The empty set.
val full : t
The set of all elements (of type elm
).
val is_empty : t -> bool
Test whether a set is empty or not.
val is_full : t -> bool
Test whether a set contains the whole type or not.
add x s
returns a set containing all elements of s
, plus x
. If x
was already in s
, then s
is returned unchanged.
remove x s
returns a set containing all elements of s
, except x
. If x
was not in s
, then s
is returned unchanged.
equal s1 s2
tests whether the sets s1
and s2
are equal, that is, contain equal elements.
Gives a finite representation of the predicate: if the boolean is false, then the predicate is given in extension. if it is true, then the complement is given
val is_finite : t -> bool
true
if the predicate can be given as a finite set (if elt
is a finite type, we can have is_finite x = false
yet x
is finite, but we don't know how to list its elements)