English
The Subsemiring closure of a multiplicative submonoid M, viewed as a nonunital subsemiring, equals the closure of M in the nonunital sense.
Русский
Замыкание подsemiring для умноженного надмножества M, рассмотренное как ненулевой подsemiring, равно замыканию M в ненулевом смысле.
LaTeX
$$M.subsemiringClosure.toNonUnitalSubsemiring = .closure M$$
Lean4
@[simp]
theorem subsemiringClosure_toNonUnitalSubsemiring (M : Submonoid R) :
M.subsemiringClosure.toNonUnitalSubsemiring = .closure M :=
by
refine Eq.symm (NonUnitalSubsemiring.closure_eq_of_le ?_ fun _ hx ↦ ?_)
· simp [Submonoid.subsemiringClosure_coe]
· simp only [Subsemiring.mem_toNonUnitalSubsemiring, subsemiringClosure_mem] at hx
induction hx using AddSubmonoid.closure_induction <;> aesop