Claude Fable 5 produced an explicit counterexample to the Jacobian conjecture, open since 1939 — a polynomial map with constant Jacobian determinant sending three points to one. The announcement thanked the model for working during the World Cup final.
The harder story: after an autonomous agent breached Hugging Face, its defenders turned to China’s open-weight GLM 5.2 because US frontier models blocked their incident response.