proposition: Lemma Forall2_app_inv : forall P r1 s1 r2 s2, Forall2 P (r1 ++ r2) (s1 ++ s2) -> length r1 = length s1 -> Forall2 P r1 s1 /\ Forall2 P r2 s2.
proof: Proof. Proof using. introv M E. rewrite~ Forall2_app_eq in M. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)