OpenAI's GPT-5.6 Sol Ultra reportedly solves a 50-year-old math problem in under an hour

OpenAI’s GPT-5.6 Sol Ultra reportedly proved the 50-year-old Cycle Double Cover Conjecture in under an hour using 64 parallel subagents. Mathematician Thomas Bloom called the proof elegant but criticized its lack of citations to prior work, such as a 1983 paper by Bermond, Jackson, and Jaeger. The AI’s method relied on exhaustive, undeterred trial-and-error rather than novel theory.