proposition: Lemma nil_eq_rev_inv : forall l, nil = rev l -> l = nil.
proof: Proof. Proof using. introv H. apply~ rev_eq_nil_inv. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)