English
Over Noetherian rings, the radical is abelian iff every solvable ideal is abelian.
Русский
Над числами безграничного множества, абелевость радикала эквивалентна тому, что каждый разрешимый идеал абелев.
LaTeX
$$$(IsNoetherian\; R\; L) : IsLieAbelian (radical\ R\ L) \iff \forall I : LieIdeal\ R\ L, IsSolvable I \Rightarrow IsLieAbelian I$$$
Lean4
theorem abelian_radical_iff_solvable_is_abelian [IsNoetherian R L] :
IsLieAbelian (radical R L) ↔ ∀ I : LieIdeal R L, IsSolvable I → IsLieAbelian I :=
by
constructor
· rintro h₁ I h₂
rw [LieIdeal.solvable_iff_le_radical] at h₂
exact (LieIdeal.inclusion_injective h₂).isLieAbelian h₁
· intro h; apply h; infer_instance