∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.Abelian C] {P Q : C}
  (f : P ⟶ Q),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Abelian.coimage.π f) (CategoryTheory.Abelian.factorThruCoimage f) =
    f