∀ (C : Type u_1) [inst : CategoryTheory.Category.{v_1, u_1} C] {A : Type u_4} [inst_1 : AddMonoid A]
  [inst_2 : CategoryTheory.HasShift C A] (x : A) (X : C),
  (CategoryTheory.Functor.commShiftIso (CategoryTheory.Functor.id C) x).hom.app X =
    CategoryTheory.CategoryStruct.id ((CategoryTheory.shiftFunctor C x).obj X)