English
If a nonunital star subalgebra s is commutative, then its topological closure is a nonunital commutative ring.
Русский
Если неединичную звездную подпалгебу s коммутативна, то ее топологическое замыкание является неединичным коммутативным кольцом.
LaTeX
$$$s.topologicalClosure\\text{ is a }\\mathrm{NonUnitalCommRing}.$$$
Lean4
/-- If a non-unital star subalgebra of a non-unital topological star algebra is commutative, then
so is its topological closure.
See note [reducible non-instances]. -/
abbrev nonUnitalCommRingTopologicalClosure [T2Space A] (s : NonUnitalStarSubalgebra R A)
(hs : ∀ x y : s, x * y = y * x) : NonUnitalCommRing s.topologicalClosure :=
{ s.topologicalClosure.toNonUnitalRing, s.toSubsemigroup.commSemigroupTopologicalClosure hs with }