proposition: Lemma gpaco3_step clo r rg: gf (gpaco3 clo rg rg) <3= gpaco3 clo r rg.
proof: Proof. intros. apply gpaco3_step_gen. eapply gf_mon. apply PR. intros. eapply gpaco3_mon. apply PR0. left; apply PR1. left; apply PR1. Qed.
imports: Program.Basics Paco(paco3 pacotac)