Claude Fable 5 shocked the math world.

Claude Fable 5 shocked the math world. Anthropic just solved an 87-year-old math problem using Fable 5 while he was watching the FIFA World Cup. The problem is called the Jacobian conjecture. Stated back in 1939, it sat on the same list as the Riemann hypothesis and P vs NP as one of the hardest unsolved problems in mathematics. Failed proofs had been piling up for six decades. On Sunday night, Levent Alpoga, a number theorist at Anthropic, set Claude Fable 5 to work on it during the World Cup final. And Fable came back with something nobody had found in 87 years. A concrete counterexample showing the conjecture was never actually true. And here's what makes this different from every other AI research claim. You don't have to take anyone's word for it. The entire counterexample fits in a single post and anyone can verify it on Wolfram Alpha in under a minute. Mathematicians did exactly that within hours. 87 years of the world's best mathematicians walking away empty-handed and Fable did it while someone was watching football.