proposition: Lemma tclosure_ind_l : forall R (P : A -> A -> Prop), (forall x y, R x y -> P x y) -> (forall y x z, R x y -> tclosure R y z -> P y z -> P x z) -> (forall x y, tclosure R x y -> P x y).
proof: Proof. Proof using. introv H1 H2 M. rewrite tclosure_eq_tclosure'l in *. induction* M. Qed.
imports: TLC(LibTactics LibLogic LibBool LibLogic LibProd LibSum)