An AI called Claude Fable 5 has produced a counterexample that appears to disprove the Jacobian conjecture, open since 1939. The maths is short enough to check by hand. The story of how it was found is not.

Mathematicians have been trying to prove the Jacobian conjecture for nearly a century, but now the Claude Fable 5 AI has apparently found a counterexample that disproves it

The Jacobian conjecture has bedeviled math experts for nearly 90 years.