English
Finitely generated additive subgroups are equivalent to finitely generated as multiplicative subgroups.
Русский
Конечнопорожденность как AddSubgroup равна FG как Subgroup в мультипликативной форме.
LaTeX
$$$\forall P : AddSubgroup H, P.FG \iff P.toSubgroup.FG$$$
Lean4
theorem fg_iff_mul_fg (P : AddSubgroup H) : P.FG ↔ P.toSubgroup.FG :=
by
rw [AddSubgroup.fg_iff_addSubmonoid_fg, Subgroup.fg_iff_submonoid_fg]
exact AddSubmonoid.fg_iff_mul_fg (AddSubgroup.toAddSubmonoid P)