proposition: Lemma gpaco13_unfold clo r rg: gpaco13 clo r rg <13= rclo13 clo (gf (gupaco13 clo (rg \13/ r)) \13/ r).
proof: Proof. intros. destruct PR. eapply rclo13_mon. apply IN. intros. destruct PR; cycle 1. right; apply H. left. _punfold H; [|apply gpaco13_def_mon]. eapply gf_mon. apply H. intros. econstructor. eapply rclo13_mon. apply PR. intros. destruct PR0; cycle 1. right. apply H0. left. eapply paco13_mon. apply H0. intros. left. apply PR0. Qed.
imports: Program.Basics Paco(paco13 pacotac)