proposition: Corollary paco13_mult: forall r, paco13 gf (paco13 gf r) <13= paco13 gf r.
proof: Proof. intros; eapply paco13_mult_strong, paco13_mon; [apply PR|..]; intros; left; assumption. Qed.
imports: Program.Basics Paco(paconotation_internal paco_internal pacotac_internal)