English
For any subset s of a module M over a ring R, the additive subgroup closure of s, viewed as a Z-submodule, is exactly the Z-span of s.
Русский
Для любого подмножества s модуля M над кольцом R аддитивное замыкание s равно Z-спану s.
LaTeX
$$$\langle s \rangle_{\mathbb{Z}} = \operatorname{span}_{\mathbb{Z}}(s)$$$
Lean4
theorem _root_.AddSubgroup.toIntSubmodule_closure (s : Set M) : (AddSubgroup.closure s).toIntSubmodule = .span ℤ s :=
(Submodule.span_le.mpr AddSubgroup.subset_closure).antisymm'
((Submodule.span ℤ s).toAddSubgroup.closure_le.mpr Submodule.subset_span)