Oct 6, 2026
Lean formalization in OpenAI math repository (Result 242)
Model / AI: OpenAI (unreleased)
machine-checked (formal proof)self-reported (formal proof)
OpenAI's internal frontier model proved and formalized in Lean the main result of 'Single-fold Diophantine representations'. Every recursively enumerable set of natural-number tuples has a polynomial Diophantine representation with exactly one complete auxiliary tuple for each member. This proves the single-fold conjecture and, consequently, the finite-fold conjecture.
Source read 2026-10-08. Cataloged from OpenAI's formalization.yaml (Family 242). The Lean development was not rebuilt locally.