Claude agents spent 11 days writing 13 million lines of Lean for the first computer-checked proof of Fermat’s Last Theorem, called an extraordinary autoformalization achievement. Fermat’s margin was too narrow; Lean’s runs to 13 million lines.
And the loop has a ship date: an insider says the model after Astra launches as AGI around November, with GPT-5.6 having helped train Astra, Astra training its successors, and one of those now training a model meant to outrun every human by mid-2027.