Jul 21, 2026, 4:19 p.m. 2 min readClaude Fable 5 just solved an 87-year-old math problem, and it matters for bitcoin. (Getty Images)SummaryAn Anthropic AI model, Claude Fable 5, helped disprove the 87-year-old Jacobian conjecture, a famous open problem in mathematics dating to 1939.The model produced a concrete counterexample that mathematicians could verify by hand within a day, showing that a certain kind of mathematical “machine” can pass standard checks yet still not be reversible.The breakthrough underscores how rapidly advancing AI capabilities are drawing speculative capital and attention away from crypto and toward computing power, chips and model builders.An artificial intelligence model has helped disprove a mathematical conjecture that had gone unsolved for 87 years, and the answer was confirmed within a day because anyone can now check it by hand.Levent Alpöge, a number theorist who works at Anthropic and previously held a fellowship at Harvard, posted the result on X on Sunday night, crediting the company's Claude Fable 5 model. The problem, called the Jacobian conjecture, had been open since 1939 and sits on mathematician Stephen Smale's influential list of unsolved problems for the century.hello there the jacobian conjecture is false thanx to my close friend akhil for asking about it and my other close friend fable for working during the world cup final((1+xy)^3 z + y^2 (1+xy) (4+3xy), y + 3 x (1+xy)^2 z + 3 x y^2 (4+3xy), 2 x - 3 x^2 y - x^3 z): \C^3\to \C^3,…— levent (@__alpoge__) July 20, 2026