How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Assuming the Axiom of Choice, Nakayama's lemma
Statement
Assume the Axiom of Choice.
Let be a commutative ring, let satisfy , and let be a finitely generated left -module. If , then .
Facts & Assumptions
Given: The Axiom of Choice (The Axiom of Choice), a commutative ring , an ideal with , and a finitely generated left -module with .
Under AC, an element lies in exactly when is a unit for every (Assuming the Axiom of Choice, an element lies in the Jacobson radical exactly when one minus any multiple is a unit). This is the only use of AC in the proof.
If for finite , then for some (Determinant trick for Nakayama).
Proof
By [L2], choose with . Since , [L1] makes a unit.
Multiplying the equality by shows for every . Therefore .
Depends on
Used by
- Assuming the Axiom of Choice, generators modulo an ideal in the Jacobson radical lift to generators Corollary
- Depth as the first nonzero Ext degree Corollary
- Euler characteristic in a proper flat family is locally constant Corollary
- Polynomial extension preserves Cohen--Macaulayness Corollary
- Upper semicontinuity of fibre cohomology dimensions Corollary
- Ramification index of a morphism of curves Definition
- Cohen–Macaulayness over a finite regular local base Example
- fields as regular local rings Example
- First-order deformations of a plane conic and of a quadric surface Example
- Ramification of the double cover y²=f(x) Example
- A birational morphism of regular surfaces factors through the blowup of a point where its inverse is undefined Lemma
- A finite module with free fibre and flat base is free over a Noetherian target Lemma
- A nonsingular formal arc on a normal Noetherian surface becomes regular Lemma
- A square-conic blowup has cubic-controlled singular successors Lemma
- Canonical pullback is surjective after blowing up a rational singular point Lemma
- Degree-p differential trace extends across normal surface valuations Lemma
- Depth at a prime is bounded by local support dimension Lemma
- Depth is infinite when the ideal acts surjectively Lemma
- depth two excludes finite punctured extension Lemma
- finite local modules admit minimal free resolutions Lemma
- Finite twisted resolutions over a regular local base Lemma
- Finite-free local criterion for cohomology and base change Lemma
- Finite-type algebraic group monomorphisms are closed immersions Lemma
- Finite-type field extensions with zero Ω Lemma
- Flat maps with geometrically regular fibres have standard smooth local presentations Lemma
- Flat schematic closure over an arbitrary valuation ring Lemma
- Free differentials imply regularity in characteristic zero Lemma
- H One Regular Local Implies Koszul Regular Lemma
- Hilbert divisor charts and the Picard diagonal Lemma
- koszul euler characteristic first element reduction Lemma
- koszul homology finite length for an ideal of definition Lemma
- Line bundles on a principal localization of a regular local ring are trivial Lemma
- Local algebra tools for elementary etale changes of classical varieties Lemma
- Local Koszul Acyclicity Inductive Converse Lemma
- Local Koszul H One Detects First Regularity Failure Lemma
- Local support and index bound for the different of a curve map Lemma
- Maximal regular sequences have a common Ext length Lemma
- minimal free resolutions unique up to chain isomorphism Lemma
- Poincare cohomology at the identity Lemma
- Positive canonical twists on projective Cohen–Macaulay curves Lemma
…and 22 more results.
Dependency tree · two levels
12 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- A. Altman and S. Kleiman, A Term of Commutative Algebra, 13th ed., Exercise 10.12 (standard reference, not scraped)
- J. S. Milne, A Primer of Commutative Algebra, v4.03, Lemma 3.9 (standard reference, not scraped)