proposition: Lemma clos_rt1n_rt : forall x y, clos_refl_trans_1n R x y -> clos_refl_trans R x y.
proof: Proof. induction 1. - constructor 2. - constructor 3 with y; auto. constructor 1; auto. Defined.
imports: CRelationClasses Equations.Init Equations.Type.Logic Equations.Type.Relation