∀ {C : Type u_1} [inst : CategoryTheory.Category.{v_1, u_1} C] [inst_1 : CategoryTheory.Abelian C] {X Y : C}
  (f : X ⟶ Y), (CategoryTheory.ShortComplex.cokernelSequence f).g = CategoryTheory.Limits.cokernel.π f