proposition: Lemma interp_ret : forall {E F R} {f : E ~> itree F} (x: R), interp f (Ret x) ≈ Ret x.
proof: Proof. intros; rewrite unfold_interp; reflexivity. Qed.
imports: Coq(Setoid Morphisms) ITree(Eq.Shallow) ITree.Core.ITreeDefinition ITree.Basics.Basics ITree.Indexed.Sum ITree.Interp.Interp ITree.Interp.Recursion ITree(Eq.Eqit Eq.UpToTaus Interp.InterpFacts Interp.RecursionFacts)