∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.HasShift C ℤ] {J : Type u_3}
  (T : J → CategoryTheory.Pretriangulated.Triangle C) [inst_2 : CategoryTheory.Limits.HasProduct fun j => (T j).obj₁]
  [inst_3 : CategoryTheory.Limits.HasProduct fun j => (T j).obj₂]
  [inst_4 : CategoryTheory.Limits.HasProduct fun j => (T j).obj₃]
  [inst_5 : CategoryTheory.Limits.HasProduct fun j => (CategoryTheory.shiftFunctor C 1).obj (T j).obj₁] (j : J),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Pretriangulated.productTriangle T).mor₁
      (CategoryTheory.Limits.Pi.π (fun j => (T j).obj₂) j) =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.Pi.π (fun j => (T j).obj₁) j) (T j).mor₁