On 6 October OpenAI published a repository of new mathematical results produced by an internal frontier model. Many of the proofs come with Lean formalizations that a computer can check step by step. Which model it is, OpenAI does not say; the results are listed in the repository.
- 6 October 2026: OpenAI published a "broad range" of new mathematical results from an internal model it does not name on GitHub.
- Many of the proofs come with formalizations in Lean, a language in which a computer checks every step. OpenAI promises more.
- According to OpenAI the average result cost about three hours of ChatGPT Pro thinking. The model is not released yet; the company is working on releasing it responsibly.
Three hours. That is how much ChatGPT Pro thinking the average result of OpenAI's new batch of mathematics cost, according to the company. The number is one of the things you can look at yourself this time.
Lean turns checking a proof into a job for a machine: you run the file and it tells you whether every step holds. A second check remains that the machine does not do: whether what is written in Lean is exactly the question mathematicians are asking. That is our reading, not OpenAI's words.
The announcement does not list the results or name the model. The repository lists them, 722 manuscripts; it does not name the model either.
What can be checked is now public: the Lean files, the ten reasoning summaries, the compute estimates. The model that produced them is not. OpenAI says it is working on releasing it responsibly, with no date.