English
There exists a canonical natural algebra homomorphism from the unitization of a nonunital subsemiring S to the subsemiring closure of S inside R, over ℕ.
Русский
Существует каноническое естественное алгебраическое гомоморфизм от единичизации неограниченного подполу полупрайса S к замыканию S внутри R над ℕ.
LaTeX
$$$\mathrm{unitization}(s) : \mathrm{Unitization}\;\mathbb{N}\;s \longrightarrow_{\mathbb{N}} R$$$
Lean4
/-- The natural `ℕ`-algebra homomorphism from the unitization of a non-unital subsemiring to
its `Subsemiring.closure`. -/
def unitization : Unitization ℕ s →ₐ[ℕ] R :=
NonUnitalSubalgebra.unitization (hSRA := AddSubmonoidClass.nsmulMemClass) s