∀ {C : Type u_1} [inst : CategoryTheory.Category.{u_2, u_1} C] [inst_1 : CategoryTheory.Abelian C]
  (Φ Ψ : CategoryTheory.Abelian.Preradical C) {Z : CategoryTheory.Functor C C} (h : Φ.quotient.comp Ψ.r ⟶ Z),
  CategoryTheory.CategoryStruct.comp (Φ.toColon Ψ).hom.left (CategoryTheory.CategoryStruct.comp (Φ.colonπ Ψ) h) =
    CategoryTheory.CategoryStruct.comp 0 h