proposition: Corollary paco12_mult: forall r, paco12 gf (paco12 gf r) <12= paco12 gf r.
proof: Proof. intros; eapply paco12_mult_strong, paco12_mon; [apply PR|..]; intros; left; assumption. Qed.
imports: Program.Basics Paco(paconotation_internal paco_internal pacotac_internal)