proposition: Lemma gpaco4_mon clo r r' rg rg' x0 x1 x2 x3 (IN: @gpaco4 clo r rg x0 x1 x2 x3) (LEr: r <4= r') (LErg: rg <4= rg'): @gpaco4 clo r' rg' x0 x1 x2 x3.
proof: Proof. destruct IN. econstructor. eapply rclo4_mon. apply IN. intros. destruct PR; [|right; apply LEr, H]. left. eapply paco4_mon. apply H. intros. destruct PR. - left. apply LErg, H0. - right. apply LEr, H0. Qed.
imports: Program.Basics Paco(paco4 pacotac)