English
Another articulation of the closure mapping between Submonoid and AddSubmonoid via Multiplicative A.
Русский
Еще одно изложение замыкания между Submonoid и AddSubmonoid через Multiplicative A.
LaTeX
$$$ \mathrm{toAddSubmonoid}'(\mathrm{closure}(S)) = \mathrm{closure}(\mathrm{Multiplicative.ofAdd}(S)) $$$
Lean4
theorem toAddSubmonoid'_closure (S : Set (Multiplicative A)) :
Submonoid.toAddSubmonoid' (Submonoid.closure S) = AddSubmonoid.closure (Multiplicative.ofAdd ⁻¹' S) :=
le_antisymm
(Submonoid.toAddSubmonoid'.to_galoisConnection.l_le <|
Submonoid.closure_le.2 <| AddSubmonoid.subset_closure (M := A))
(AddSubmonoid.closure_le.2 <| Submonoid.subset_closure (M := Multiplicative A))