English
If a subsemiring s is commutative under multiplication, then its topological closure is a commutative semiring.
Русский
Если произведение в подполукольце s коммутирует, то замыкание s по топологии также является коммутативным полукольцом.
LaTeX
$$CommSemiring (topologicalClosure s) (hs : ∀ x y : s, x y = y x)$$
Lean4
/-- If a subsemiring of a topological semiring is commutative, then so is its
topological closure.
See note [reducible non-instances]. -/
abbrev commSemiringTopologicalClosure [T2Space R] (s : Subsemiring R) (hs : ∀ x y : s, x * y = y * x) :
CommSemiring s.topologicalClosure :=
{ s.topologicalClosure.toSemiring, s.toSubmonoid.commMonoidTopologicalClosure hs with }