English
For nonunital subalgebras, S1.starClosure ≤ S2 if and only if S1 ≤ S2 (as nonunital subalgebras).
Русский
Для неабстрактных подпалей S1.starClosure ≤ S2 тогда и только тогда, когда S1 ≤ S2 (как небходимые неединичные подпалей).
LaTeX
$$$ S_1^{*} \le S_2 \iff S_1 \le S_2^{\text{toNonUnitalSubalgebra}} $$$
Lean4
theorem starClosure_le {S₁ : NonUnitalSubalgebra R A} {S₂ : NonUnitalStarSubalgebra R A}
(h : S₁ ≤ S₂.toNonUnitalSubalgebra) : S₁.starClosure ≤ S₂ :=
NonUnitalStarSubalgebra.toNonUnitalSubalgebra_le_iff.1 <|
sup_le h fun x hx => (star_star x ▸ star_mem (show star x ∈ S₂ from h <| (S₁.mem_star_iff _).1 hx) : x ∈ S₂)