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 be regular local of dimension , and let . Then is regular local, of dimension and embedding dimension .
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.
regular system of parameters equivalent basis: Let be a nonzero Noetherian local ring of dimension , and let . Then is a regular system of parameters if and only if its classes form a -basis of . In particular every lift of a cotangent basis in a regular local ring generates and is a system of parameters.
dimension at most embedding dimension: Every nonzero commutative Noetherian local ring satisfies .
Local dimension is the minimal number of generators of an ideal with maximal radical: Let be a finite-dimensional Noetherian local ring of dimension . Then is the least integer for which there exists an -generated ideal with .
Proof
Extend the nonzero class of to a basis of and lift it. Under the assumed AC, [F1] makes the resulting elements generators of ; their last images generate the maximal ideal of . Hence . The hypotheses force and .
Let , which is finite by the embedding bound. Lift radical generators of the maximal ideal of . Together with they generate an ideal of with radical , so . Combining proves all the assertions, including the field quotient when .