proposition: Corollary paco2_mult: forall r, paco2 gf (paco2 gf r) <2= paco2 gf r.
proof: Proof. intros; eapply paco2_mult_strong, paco2_mon; [apply PR|..]; intros; left; assumption. Qed.
imports: Program.Basics Paco(paconotation_internal paco_internal pacotac_internal)