OpenAI reports a four-variable stable-coordinate counterexample

An explicit degree-five polynomial in four complex variables is not a coordinate there but becomes a coordinate after one new variable; each fiber is affine three-space without an ambient rectification.

Sources for this record

What was already known

The stable-coordinate statement was known to hold over the complex numbers in two and three variables, making four the first possible dimension for such a counterexample in the manuscript’s account.

AI involvement AI-led

OpenAI credits itself as manuscript author and states that its internal frontier model produced the results in this release. Individual human input is not detailed enough to establish task-only autonomy.

OpenAI is named as author on the manuscript, and its release attributes the results to an internal frontier model. The individual human input is not detailed enough to establish autonomy.

Importance Major

Refutes the stable-coordinate conjecture at its first possible complex dimension and gives a nonrectifiable affine-three-space embedding.

Limitations

The selected result concerns four variables. It is a distinct polynomial-coordinate statement related to, but not identical with, the fourfold cancellation counterexample.

Technical verification Formal (Lean 4)

OpenAI reports a Lean proof matching the selected claim.

Formal checking

The pinned Lean note covers the explicit degree-five one-stable polynomial, its failure to be a coordinate, and its nonrectifiable affine-three-space fibers.

Checker
OpenAI-reported Lean 4 / Comparator
Scope
An explicit degree-five polynomial in four complex variables is not a coordinate there but becomes a coordinate after one new variable; each fiber is affine three-space without an ambient rectification.
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Few

Few is the default when evidence for a higher level is insufficient. No named person is documented as explaining the central argument for this assessed contribution.

Correction and publication history

2026-10-18 · publication

Primary manuscript, attribution, prior-work, and scoped checking review for non-notifying local inclusion.

Read this published revision