proposition: Lemma transU_compose: compose transU transU <3= transU.
proof: Proof. intros. destruct PR. destruct REL. econstructor; try eapply eqit_trans; eauto; auto_ctrans. Qed.
imports: Coq(Setoid Morphisms Relations) Paco(paco) ITree(Basics.Utils Core.ITreeDefinition Eq.Eqit Eq.Paco2 Eq.Shallow)