proposition: Lemma gpaco4_step_gen clo r rg: gf (gpaco4 clo (rg \4/ r) (rg \4/ r)) <4= gpaco4 clo r rg.
proof: Proof. intros. econstructor. apply rclo4_base. left. pstep. eapply gf_mon. apply PR. intros. destruct PR0. eapply rclo4_mon. apply IN. intros. destruct PR0. - left. eapply paco4_mon. apply H. intros. destruct PR0; apply H0. - right. apply H. Qed.
imports: Program.Basics Paco(paco4 pacotac)