∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C]
  {X Y Z : C} (f : X ⟶ Y) (g : Y ⟶ Z) [inst_2 : CategoryTheory.Limits.HasKernel f] [inst_3 : CategoryTheory.Mono g],
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.kernel.ι (CategoryTheory.CategoryStruct.comp f g)) f = 0