∀ {α : Type u_1} {β : Type u_2} [inst : TopologicalSpace α] [inst_1 : TopologicalSpace β] [inst_2 : Semiring β]
  [inst_3 : IsTopologicalSemiring β] (x y : C(α, β)),
  (↑ContinuousMap.coeFnAddMonoidHom).toFun (x + y) =
    (↑ContinuousMap.coeFnAddMonoidHom).toFun x + (↑ContinuousMap.coeFnAddMonoidHom).toFun y