∀ (C : Type u) [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.Preadditive C]
  [inst_2 : CategoryTheory.HasShift C ℤ] {X Y : CategoryTheory.Pretriangulated.Triangle C} (f : X ⟶ Y),
  ((CategoryTheory.Pretriangulated.rotate C).map f).hom₃ = (CategoryTheory.shiftFunctor C 1).map f.hom₁