∀ {J : Type u_4} {C : Type u_2} [inst : CategoryTheory.Category.{u_3, u_4} J]
  [inst_1 : CategoryTheory.Category.{u_1, u_2} C] [inst_2 : CategoryTheory.Limits.HasZeroMorphisms C]
  {F : CategoryTheory.Functor J (CategoryTheory.ShortComplex C)} (c : CategoryTheory.Limits.Cocone F)
  (h₂ : CategoryTheory.Limits.IsColimit (CategoryTheory.ShortComplex.π₂.mapCocone c))
  (h₃ : CategoryTheory.Limits.IsColimit (CategoryTheory.ShortComplex.π₃.mapCocone c))
  (s : CategoryTheory.Limits.Cocone F) (j : J),
  CategoryTheory.CategoryStruct.comp ((CategoryTheory.ShortComplex.π₂.mapCocone c).ι.app j)
      (CategoryTheory.CategoryStruct.comp (h₂.desc (CategoryTheory.ShortComplex.π₂.mapCocone s)) s.pt.g) =
    CategoryTheory.CategoryStruct.comp ((CategoryTheory.ShortComplex.π₂.mapCocone c).ι.app j)
      (CategoryTheory.CategoryStruct.comp c.pt.g (h₃.desc (CategoryTheory.ShortComplex.π₃.mapCocone s)))