Woofun AI reports that OpenAI researcher Ethan Knight announced on X that GPT-5.6 Sol Ultra generated a proof for the "Cycle Double Cover Conjecture" in approximately one hour. Utilizing up to 64 parallel sub-agents without internet access, the model produced a three-page paper reducing the problem to cubic graphs via the 8-flow theorem and GF(3) labels.

The result has not undergone peer review or formal verification in Lean or Coq. University of Manchester mathematician Thomas Bloom rated the proof "excellent" but cited insufficient bibliographic references.