∀ (J : Type u_1) (C : Type u_2) [inst : CategoryTheory.Category.{v_1, u_1} J]
  [inst_1 : CategoryTheory.Category.{v_2, u_2} C] [inst_2 : CategoryTheory.Limits.HasZeroMorphisms C]
  (X : CategoryTheory.Functor J (CategoryTheory.ShortComplex C)) (X_1 : J),
  (((CategoryTheory.ShortComplex.FunctorEquivalence.counitIso J C).hom.app X).app X_1).τ₂ =
    CategoryTheory.CategoryStruct.id (X.obj X_1).X₂