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-rw-r--r--theories/Init/Peano.v8
1 files changed, 1 insertions, 7 deletions
diff --git a/theories/Init/Peano.v b/theories/Init/Peano.v
index f449d8383..216ca35af 100644
--- a/theories/Init/Peano.v
+++ b/theories/Init/Peano.v
@@ -50,13 +50,7 @@ Qed.
(** Injectivity of successor *)
-Theorem eq_add_S : forall n m:nat, S n = S m -> n = m.
-Proof.
- intros n m Sn_eq_Sm.
- replace (n=m) with (pred (S n) = pred (S m)) by auto using pred_Sn.
- rewrite Sn_eq_Sm; trivial.
-Qed.
-
+Definition eq_add_S n m (H: S n = S m): n = m := f_equal pred H.
Hint Immediate eq_add_S: core.
Theorem not_eq_S : forall n m:nat, n <> m -> S n <> S m.