Library Coq.Arith.Peano_dec



Require Import Decidable.

Open Local Scope nat_scope.

Implicit Types m n x y : nat.

Theorem O_or_S : forall n, {m : nat | S m = n} + {0 = n}.

Theorem eq_nat_dec : forall n m, {n = m} + {n <> m}.

Hint Resolve O_or_S eq_nat_dec: arith.

Theorem dec_eq_nat : forall n m, decidable (n = m).