∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C]
  {P Q : C} (f : P ⟶ Q) [inst_2 : CategoryTheory.Limits.HasCokernel f] [inst_3 : CategoryTheory.Limits.HasKernel f]
  [inst_4 : CategoryTheory.Limits.HasCokernel (CategoryTheory.Limits.kernel.ι f)],
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.cokernel.desc (CategoryTheory.Limits.kernel.ι f) f ⋯)
      (CategoryTheory.Limits.cokernel.π f) =
    0