∀ {T : Type u_1} [inst : CategoryTheory.Category.{v_1, u_1} T] {P Q : CategoryTheory.MorphismProperty T} {X : T}
  [inst_1 : Q.IsMultiplicative] {A B : P.Over Q X} (f : A ⟶ B) {Z : T}
  (h : (CategoryTheory.Functor.fromPUnit X).obj B.right ⟶ Z),
  CategoryTheory.CategoryStruct.comp f.left (CategoryTheory.CategoryStruct.comp B.hom h) =
    CategoryTheory.CategoryStruct.comp A.hom h