fact: Definition mrecursive {D E} (f : D ~> itree (D +' E)) : (D +' E) ~> itree E := case_ (mrec f) ITree.trigger.
imports: Coq(Setoid Morphisms) ITree(Eq.Shallow) ITree.Core.ITreeDefinition ITree.Basics.Basics ITree.Indexed.Sum ITree.Interp.Interp ITree.Interp.Recursion