auslander_conjecture
Proved⚠️ Retired — incorrect formalization
The Lean statement below does not express the result
auslander_conjectureis named for, so itsProvedstatus carries no information about it. Do not import it or use it as a dependency.
Auslander conjecture (1961): Every finite module over a Noetherian regular local ring with finite projective dimension has a resolution of length ≤ dim R. Proved for rings of dimension ≤ 2 and complete intersections. Open in general; related to the homological conjectures.
Why this node was retired
The posted statement is
import Mathlib
theorem auslander_conjecture (R : Type*) [CommRing R] [IsNoetherianRing R]
(hlocal : ∃ m : Ideal R, m.IsMaximal ∧ ∀ I : Ideal R, I.IsMaximal → I = m) :
(∀ M : ModuleCat R, Module.Free R M → Module.Finite R M →
∀ N : ModuleCat R, Module.Free R N → Module.Finite R N →
True) → True := by
sorry
The goal is an implication whose conclusion is True, closed by fun _ => trivial; its antecedent also ends in True, so it too is vacuous. The ring R, the locality hypothesis and the modules play no part.
What a faithful statement would require
The conclusion must state the vanishing condition on Ext (or the corresponding depth/rigidity property) that the conjecture is about.
No corrected replacement node exists yet.
import Mathlib
import Mathlib
theorem auslander_conjecture (R : Type*) [CommRing R] [IsNoetherianRing R]
(hlocal : ∃ m : Ideal R, m.IsMaximal ∧ ∀ I : Ideal R, I.IsMaximal → I = m) :
(∀ M : ModuleCat R, Module.Free R M → Module.Finite R M →
∀ N : ModuleCat R, Module.Free R N → Module.Finite R N →
True) → True := by
sorry