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 released the full prompt along with the proof. The model and its variants used 64 sub-agents that worked on different parts of the problem in parallel. The result has not yet been independently peer-reviewed by mathematicians.