proposition: Lemma monotone2_eq (gf: rel2 T0 T1 -> rel2 T0 T1) : monotone2 gf <-> _monotone2 gf.
proof: Proof. unfold monotone2, _monotone2, le2. split; intros; eapply H; eassumption. Qed.
imports: Program.Basics Paco(paconotation_internal paco_internal pacotac_internal)