proposition: Lemma map_id : forall A (l:list A), map id l = l.
proof: Proof. Proof using. introv. induction~ l. rew_listx. fequals~. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)