English
Under a Finite group G with a decidable predicate for membership in the commutator subgroup, the abelianization is finite.
Русский
Для конечной группы G с разрешимым предикатом принадлежности к коммутатору абелизация конечна.
LaTeX
$$$ [Finite(G) \land DecidablePred(\cdot \in commutator(G))] \Rightarrow Finite(Abelianization(G)) $$$
Lean4
@[simp]
theorem univ_addEquiv : (Finset.univ : Finset (ℤ ≃+ ℤ)) = .cons (.neg ℤ) {.refl ℤ} (by simp [AddEquiv.ext_int_iff]) :=
rfl