Polynomial Hitting Lists for Noncommutative Rational Formulas

OpenAI

Given unary n and a size bound s, a deterministic machine constructs in polynomial bit time a polynomial-size list of rational matrix tuples of polynomial total output length and common polynomial dimension. Every admissible nonzero noncommutative rational formula over Q of size at most s has a defined, invertible evaluation on a listed tuple.

Sources for this record

What was already known

Deterministic polynomial-time white-box tests were known. For unrestricted inverse nesting, the cited black-box rational-formula hitting sets were quasipolynomial in size.

AI involvement AI-led

OpenAI authors the manuscript and credits its internal model with the construction and proof artifacts. No human origin for the central hitting-list method is documented.

OpenAI authorship and the release's model-production account support AI leadership; autonomous session provenance is absent.

Importance Notable

The construction would reduce the black-box list size and generation time to polynomial bounds for the stated rational formulas.

Limitations

Inverse depth and rational constant heights are unrestricted. Arbitrary circuits and coefficient fields other than Q are outside the claim.

Technical verification Formal (Lean 4 with Mathlib)

The cited Lean proof module states OAI.RationalHitting.main for a fixed finite-state machine, exact inverse-domain semantics, polynomial bit time, output length and matrix dimension, and an invertible hit for each admissible nonzero formula. This is source-reported machine verification, not a compilation or independent audit here.

Independent checking

Lean proof OAI.RationalHitting.main with the RationalHitting comparator statement and finite-state implementation

Checker
Lean 4 kernel, as reported by the OpenAI math release
Scope
Polynomial-time rational matrix hitting lists with exact inverse domains and invertible hits for all bounded-size admissible nonzero formulas over Q
Basis
Reported by the linked checker
Evidence source

Human understanding Few

No named human explanation of the model's Wronskian expansion, division-algebra lift and rational generator is documented. Few is the evidence default.

Correction and publication history

2026-10-18 · publication

The construction would reduce the black-box list size and generation time to polynomial bounds for the stated rational formulas.

Read this published revision