English
For any submodule S of P, P is Noetherian if and only if both S is Noetherian and P/S is Noetherian.
Русский
Для любого подмодуля S P верно: P Noetherian тогда и только тогда, когда S Noetherian и P/S Noetherian.
LaTeX
$$$IsNoetherian R P \iff IsNoetherian R S \land IsNoetherian R (P/S)$$$
Lean4
theorem isNoetherian_iff_submodule_quotient (S : Submodule R P) :
IsNoetherian R P ↔ IsNoetherian R S ∧ IsNoetherian R (P ⧸ S) :=
by
refine ⟨fun _ ↦ ⟨inferInstance, inferInstance⟩, fun ⟨_, _⟩ ↦ ?_⟩
apply isNoetherian_of_range_eq_ker S.subtype S.mkQ
rw [Submodule.ker_mkQ, Submodule.range_subtype]