OpenAI just published a Lean-checked proof that smooth three-dimensional Navier-Stokes can develop a singularity in finite time, resolving statements C and D of the Clay Millennium Prize problem that has sat open for about ninety years.

The writeup and formalization came from an internal system they describe as significantly more capable than GPT-6 Astra. The result is a vortex that spirals inward and stretches until velocity blows up while energy stays finite, which is the continuum breakdown the prize statement asked about.

They are not claiming the prize. The receipt that matters for the rest of us is a machine-produced, machine-verified answer on a Millennium Prize problem, released the same week the work finished.