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.
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- 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 .
Depends on
Used by
- Contact order of two regular components at a point Definition
- Order of an ideal sheaf at a point Definition
- Strict normal crossings divisor on a regular surface Definition
- regular local ambient cover minimal dimension Example
- A point blowup lowers pairwise contact order by one and separates transverse branches Lemma
- A triple-cubic surface branch reduces after two successors Lemma
- Blowing up a multiple point separates pairwise transverse components Lemma
- Codimension-one components of a maximal-order support Lemma
- Graded Nakayama and the Hesselink regularity comparison Lemma
- Point blowups of regular surfaces stay regular, with rational exceptional curves at two-dimensional local rings Lemma
- regular local regular quotient ideal is parameter generated Lemma
- Surface derivations and regular hypersurfaces Lemma
- The double-plus-simple cubic surface branch terminates Lemma
- Vector-bundle maps on a regular punctured spectrum are recovered from parameter thickenings Lemma
- Blowing up a rational point of a smooth surface Theorem
- Finite étale covers extend across the closed point of a regular local ring Theorem
- Point blowups of regular surfaces stay regular, with rational exceptional fibre over the residue field Theorem
- quotient and lifting regularity across a regular element Theorem
- regular local rings are domains and cohen macaulay Theorem
- Regular local rings are unique factorization domains Theorem
- Resolution of reduced plane curves by point blowups and the delta recurrence Theorem
Dependency tree · two levels
13 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
- Proposition 12.7, p.115 (standard reference, not scraped)