Researcher Dmitry Rybin has claimed that GPT 5.6 Pro disproved the nearly 30-year-old Dinitz-Garg-Goemans conjecture after working on it for nearly 5 hours. Rybin also shared his chats, which show him giving prompts like "do a breakthrough" and "enough of partial results, let's finish". GPT 5.6 Pro's graph counterexample allegedly proves that unsplittable versions can cost more.