English
Under suitable conditions, comap f of bracket [I,N₂] equals bracket I of comap f N₂.
Русский
При некоторых условиях прообраз по f скобки [I,N₂] равен скобке [I, прообраз f N₂].
LaTeX
$$$$ \operatorname{comap} f\,[I,N_2] = [I, \operatorname{comap} f N_2]. $$$$
Lean4
@[simp]
theorem bot_lie : ⁅(⊥ : LieIdeal R L), N⁆ = ⊥ :=
by
suffices ⁅(⊥ : LieIdeal R L), N⁆ ≤ ⊥ by exact le_bot_iff.mp this
rw [lieIdeal_oper_eq_span, lieSpan_le]; rintro m ⟨⟨x, hx⟩, n, hn⟩; rw [← hn]
change x ∈ (⊥ : LieIdeal R L) at hx; rw [mem_bot] at hx; simp [hx]