proposition: Lemma gpaco4_gen_guard clo r rg: gpaco4 clo r (rg \4/ r) <4= gpaco4 clo r rg.
proof: Proof. intros. destruct PR. econstructor. eapply rclo4_mon. apply IN. intros. destruct PR; [|right; apply H]. left. eapply paco4_mon_gen; intros. apply H. apply PR. destruct PR. apply H0. right. apply H0. Qed.
imports: Program.Basics Paco(paco4 pacotac)