Section Clos_Refl_Trans.
Local Notation "R *" := (clos_refl_trans R)
(at level 8, no associativity, format "R *").
(** Correctness of the reflexive-transitive closure operator *)
(** Idempotency of the reflexive-transitive closure operator *)

Lemma clos_rt_idempotent : inclusion (R*)* R*.