∀ {R : Type u_2} {A : Type u_1} [inst : CommSemiring R] [inst_1 : Semiring A] [inst_2 : Algebra R A]
  {S T : Subalgebra R A} (h : S ≤ T) (x x_1 : ↥S), Set.inclusion h (x + x_1) = Set.inclusion h (x + x_1)