proposition: Lemma self_eq_app_r_inv : forall l1 l2, l2 = l1 ++ l2 -> l1 = nil.
proof: Proof. Proof using. intros. applys* app_r_eq_self_inv. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)