proposition: Lemma clos_trans_power (T : X -> X -> Prop) x y : clos_trans _ T x y -> exists k, power k T x y.
proof: Proof. rewrite clos_trans_tn1_iff. induction 1. exists 0; auto. destruct IHclos_trans_n1 as [k pkyz]. exists (S k). simp power. now exists y. Qed.
imports: Equations(Equations) Examples.Fin Relations Utf8 Relations Wellfounded Setoid RelationClasses Morphisms Lia Bool List Arith String Coq(FunctionalExtensionality)