∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {X Y : C} [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C]
  (f : X ⟶ Y) [inst_2 : CategoryTheory.Limits.HasKernel f],
  CategoryTheory.Limits.kernelSubobjectIso f = CategoryTheory.Subobject.underlyingIso (CategoryTheory.Limits.kernel.ι f)