OpenAI's GPT-5.6 Sol Ultra Solves Decades-Old Math Conjecture in Under an Hour

OpenAI's newest model, GPT-5.6 Sol Ultra, has generated a machine-verified proof of the Cycle Double Cover Conjecture. The problem, posed in the 1970s by mathematicians George Szekeres and Paul Seymour, was solved in under an hour.

The conjecture states that for any graph without bridges, a collection of cycles can cover every edge exactly twice. A comprehensive general proof had long remained elusive.

The proof was published as a PDF on July 10, 2026, authored entirely by the AI model. It reportedly uses the 8-flow theorem and linear algebra over a finite field.

The solution coincides with the limited rollout of OpenAI's GPT-5.6 series. The model's architecture deployed 64 specialized subagents working in parallel to tackle the problem.

The AI research community and mathematicians will now focus on verification. A machine-verified proof confirms logical steps, but experts seek to understand the reasoning. Successful validation would mark a landmark achievement in AI's intellectual capability.