∀ {T : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} T] {P : CategoryTheory.MorphismProperty T}
  (Q : CategoryTheory.MorphismProperty T) [inst_1 : Q.IsMultiplicative] [inst_2 : P.IsStableUnderComposition]
  [inst_3 : P.IsMultiplicative] (X : T) (f : X ⟶ X) (hf : f = CategoryTheory.CategoryStruct.id X) (Y : P.Over Q X),
  CategoryTheory.CategoryStruct.comp
      (CategoryTheory.Iso.refl ((CategoryTheory.MorphismProperty.Over.map Q ⋯).obj Y).left).hom
      ((CategoryTheory.Functor.id (P.Over Q X)).obj Y).hom =
    ((CategoryTheory.MorphismProperty.Over.map Q ⋯).obj Y).hom