English
In a ring R, the bottom ideal of the quotient ring R/I is maximal if and only if I is a maximal ideal in R.
Русский
В кольце R нулевой идеал в R/I максимален тогда и только тогда, когда I максимальный идеал в R.
LaTeX
$$$ (\bot : \text{Ideal}(R/I)).IsMaximal \iff I.IsMaximal $$$
Lean4
@[simp]
theorem bot_quotient_isMaximal_iff (I : Ideal R) [I.IsTwoSided] : (⊥ : Ideal (R ⧸ I)).IsMaximal ↔ I.IsMaximal :=
⟨fun hI => mk_ker (I := I) ▸ comap_isMaximal_of_surjective (Quotient.mk I) Quotient.mk_surjective (K := ⊥) (H := hI),
fun hI => by
letI := Quotient.divisionRing I
exact bot_isMaximal⟩