∀ {C : Type u_1} [inst : CategoryTheory.EnrichedCategory CategoryTheory.Cat C] {a b c d : CategoryTheory.CatEnriched C}
  {f f' : a ⟶ b} (η : f ⟶ f') (g : b ⟶ c) (h : c ⟶ d),
  CategoryTheory.CatEnriched.hComp η (CategoryTheory.CategoryStruct.id (CategoryTheory.CategoryStruct.comp g h)) =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.eqToIso ⋯).inv
      (CategoryTheory.CategoryStruct.comp
        (CategoryTheory.CatEnriched.hComp (CategoryTheory.CatEnriched.hComp η (CategoryTheory.CategoryStruct.id g))
          (CategoryTheory.CategoryStruct.id h))
        (CategoryTheory.eqToIso ⋯).hom)