proposition: Lemma gpaco2_step clo r rg: gf (gpaco2 clo rg rg) <2= gpaco2 clo r rg.
proof: Proof. intros. apply gpaco2_step_gen. eapply gf_mon. apply PR. intros. eapply gpaco2_mon. apply PR0. left; apply PR1. left; apply PR1. Qed.
imports: Program.Basics Paco(paco2 pacotac)