proposition: Lemma Forall_mem_inv : forall P l x, Forall P l -> mem x l -> P x.
proof: Proof. Proof using. introv F I. rewrite Forall_eq_forall_mem in F. apply~ F. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)