proposition: Lemma gpaco0_mon clo r r' rg rg' (IN: @gpaco0 clo r rg) (LEr: r <0= r') (LErg: rg <0= rg'): @gpaco0 clo r' rg'.
proof: Proof. destruct IN. econstructor. eapply rclo0_mon. apply IN. intros. destruct PR; [|right; apply LEr, H]. left. eapply paco0_mon. apply H. intros. destruct PR. - left. apply LErg, H0. - right. apply LEr, H0. Qed.
imports: Program.Basics Paco(paco0 pacotac)