English
Let S : ι → Submonoid M^{op}. Then (iInf S).unop = ⨅ i, (S i).unop.
Русский
Пусть S : ι → подмономоды M^{op}. Тогда (iInf S).unop = ⨅ i, (S i).unop.
LaTeX
$$$ (\iInf S).unop = \big\wedge_{i} (S(i)).unop $$$
Lean4
theorem toSubmonoid_closure (S : Set A) :
(AddSubmonoid.toSubmonoid) (AddSubmonoid.closure S) = Submonoid.closure (Multiplicative.toAdd ⁻¹' S) :=
le_antisymm
(AddSubmonoid.toSubmonoid.to_galoisConnection.l_le <|
AddSubmonoid.closure_le.2 <| Submonoid.subset_closure (M := Multiplicative A))
(Submonoid.closure_le.2 <| AddSubmonoid.subset_closure (M := A))