∀ {S : Type u_2} {A : Type u_1} [inst : NonUnitalCommCStarAlgebra A] [inst_1 : SetLike S A]
  [inst_2 : NonUnitalSubringClass S A] [inst_3 : SMulMemClass S ℂ A] [inst_4 : StarMemClass S A] (s : S)
  [h_closed : IsClosed ↑s] (a b : ↥s), a + b = b + a