OpenAI's GPT 5.6 Sol Ultra solves 50-yr-old math problem in 1 hour

OpenAI's GPT-5.6 Sol Ultra proved the Cycle Double Cover Conjecture math problem, unsolvable since 1973, in under an hour and published the proof and released the full prompt. The model and its variants used a 64 sub-agents that worked on different parts of the problem in parallel. The result has not yet been independently peer-reviewed by mathematicians.