proposition: Lemma eqitree_inv_Ret_r {E R} (t : itree E R) r : t ≅ (Ret r) -> observe t = RetF r.
proof: Proof. intros; punfold H; inv H; try inv CHECK; eauto. Qed.
imports: Coq(Structures.Orders Program Setoid Morphisms Relations) Paco(paco) ITree(Basics.Basics Basics.Utils Basics.HeterogeneousRelations Core.ITreeDefinition Eq.Paco2 Eq.Shallow)