English
If f: L1 → L2 is surjective and L1 is LieAbelian, then L2 is LieAbelian.
Русский
Если f: L1 → L2 сюръективно и L1 абелев по Ли, то L2 абелев по Ли.
LaTeX
$$IsLieAbelian L2$$
Lean4
theorem isLieAbelian {R : Type u} {L₁ : Type v} {L₂ : Type w} [CommRing R] [LieRing L₁] [LieRing L₂] [LieAlgebra R L₁]
[LieAlgebra R L₂] {f : L₁ →ₗ⁅R⁆ L₂} (h₁ : Function.Surjective f) (h₂ : IsLieAbelian L₁) : IsLieAbelian L₂ :=
{
trivial := fun x y => by
obtain ⟨u, rfl⟩ := h₁ x
obtain ⟨v, rfl⟩ := h₁ y
rw [← LieHom.map_lie, trivial_lie_zero, LieHom.map_zero] }