diff --git a/theories/list.v b/theories/list.v index 426a5ce62888f9b389f61f53fddf62c9c21df3a9..f2d9a5d0e24c369635c4313a663f8b9d54257e32 100644 --- a/theories/list.v +++ b/theories/list.v @@ -1697,9 +1697,13 @@ Lemma Permutation_nil l : l ≡ₚ [] ↔ l = []. Proof. split; [by intro; apply Permutation_nil | by intros ->]. Qed. Lemma Permutation_singleton l x : l ≡ₚ [x] ↔ l = [x]. Proof. split; [by intro; apply Permutation_length_1_inv | by intros ->]. Qed. -Definition Permutation_skip := @perm_skip A. -Definition Permutation_swap := @perm_swap A. -Definition Permutation_singleton_inj := @Permutation_length_1 A. + +Lemma Permutation_skip x l l' : l ≡ₚ l' → x :: l ≡ₚ x :: l'. +Proof. apply perm_skip. Qed. +Lemma Permutation_swap x y l : y :: x :: l ≡ₚ x :: y :: l. +Proof. apply perm_swap. Qed. +Lemma Permutation_singleton_inj x y : [x] ≡ₚ [y] → x = y. +Proof. apply Permutation_length_1. Qed. Global Instance Permutation_cons x : Proper ((≡ₚ) ==> (≡ₚ)) (@cons A x). Proof. by constructor. Qed.