∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.HasShift C ℤ]
  [inst_2 : CategoryTheory.Preadditive C] (T₁ T₂ : CategoryTheory.Pretriangulated.Triangle C) (e₁ : T₁.obj₁ ≅ T₂.obj₁)
  (e₃ : T₁.obj₃ ≅ T₂.obj₃),
  CategoryTheory.CategoryStruct.comp T₁.mor₃ ((CategoryTheory.shiftFunctor C 1).map e₁.hom) =
      CategoryTheory.CategoryStruct.comp e₃.hom T₂.mor₃ →
    CategoryTheory.CategoryStruct.comp ((CategoryTheory.shiftFunctor C (-1)).mapIso e₃).hom
        (CategoryTheory.Arrow.mk T₂.invRotate.mor₁).hom =
      CategoryTheory.CategoryStruct.comp (CategoryTheory.Arrow.mk T₁.invRotate.mor₁).hom e₁.hom