Alphabeta Math
LemmaStatement: Literature-sourcedProof: AI-adaptedPipeline-generatedverified 2026-09-24 (gpt-6-sol)
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.

regular local quotient by parameter is regular

Statement

Assume the Axiom of Choice (The Axiom of Choice). Let (R,m,k) be regular local of dimension d, and let x∈m∖m2. Then R/(x) is regular local, of dimension and embedding dimension d−1.

Facts & Assumptions

Given: The objects and hypotheses in the statement. We work with the Axiom of Choice; cited dependent-choice and resolution-existence hypotheses are retained.

[F1]

regular system of parameters equivalent basis: Let (R,m,k) be a nonzero Noetherian local ring of dimension d, and let x=(x1,…,xd)∈md. Then x is a regular system of parameters if and only if its classes form a k-basis of m/m2. In particular every lift of a cotangent basis in a regular local ring generates m and is a system of parameters.

[F2]

dimension at most embedding dimension: Every nonzero commutative Noetherian local ring R satisfies dim⁡R≤edim⁡R<∞.

[F3]

Local dimension is the minimal number of generators of an ideal with maximal radical: Let (R,m) be a finite-dimensional Noetherian local ring of dimension d<∞. Then d is the least integer n for which there exists an n-generated ideal J⊆R with J=m.

Proof

1.1F1given

Extend the nonzero class of x to a basis of m/m2 and lift it. Under the assumed AC, [F1] makes the resulting d elements generators of m; their last d−1 images generate the maximal ideal of S=R/(x). Hence edim⁡S≤d−1. The hypotheses force d≥1 and S≠0.

2.1F3F2step 1.1algebra∎

Let t=dim⁡S, which is finite by the embedding bound. Lift t radical generators of the maximal ideal of S. Together with x they generate an ideal of R with radical m, so d≤t+1. Combining d−1≤t≤edim⁡S≤d−1 proves all the assertions, including the field quotient when d=1.

Depends on

Used by

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Sources