English
The image of zpowers x under the additive functor of multiplication equals the subgroup of multiples of Additive.ofMul x: Additive.ofMul '' (Subgroup.zpowers x) = AddSubgroup.zmultiples (Additive.ofMul x).
Русский
Образ zpowers(x) под отображением Additive.ofMul равенzmultiples(Additive.ofMul x).
LaTeX
$$$\operatorname{Additive.ofMul} '' (\operatorname{zpowers}(x)) = \operatorname{AddSubgroup.zmultiples}(\operatorname{Additive.ofMul}(x))$$$
Lean4
theorem ofMul_image_zpowers_eq_zmultiples_ofMul {x : G} :
Additive.ofMul '' (Subgroup.zpowers x : Set G) = AddSubgroup.zmultiples (Additive.ofMul x) :=
by
ext
exact Set.mem_image_iff_of_inverse (congrFun rfl) (congrFun rfl)