∀ {C : Type u_1} {D : Type u_2} [inst : CategoryTheory.Category.{v_1, u_1} C]
  [inst_1 : CategoryTheory.Category.{v_2, u_2} D] {A : Type u_5} [inst_2 : AddMonoid A]
  [inst_3 : CategoryTheory.HasShift D A] (self : CategoryTheory.SingleFunctors C D A) (n a a' : A) (ha' : n + a = a'),
  self.shiftIso n a a' ha' = self.shiftIso n a a' ha'