proposition: Lemma rev_rev : forall l, rev (rev l) = l.
proof: Proof. Proof using. intros. induction~ l. { rewrite rev_cons, rev_last. fequals. } Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)