∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {X Y : CategoryTheory.Limits.FormalCoproduct C} (e : X.I ≃ Y.I)
  (h : (i : X.I) → X.obj i ≅ Y.obj (e i)) (a : X.I),
  (CategoryTheory.Limits.FormalCoproduct.isoOfComponents e h).hom.f a = e a