proposition: Lemma Forall_cons_inv_tail : forall P l x, Forall P (x::l) -> Forall P l.
proof: Proof. Proof using. introv H. rewrite* Forall_cons_eq in H. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)