Google Deepmind's AlphaProof Nexus solves decades-old math problems for a few hundred dollars

The cost figure is the buried lede: at a few hundred dollars per solved open problem, the economic barrier to automated theorem proving has dropped far enough that academic and industrial research teams can treat it as a line item rather than a moonshot budget. That changes who can afford to use this, not just who built it.

This is largely disconnected from recent activity in our archive, as we have no prior coverage to anchor it to. It belongs to a cluster of stories about AI systems that trade generality for verifiability, a design philosophy gaining traction across code synthesis and formal methods. The choice to build on Lean rather than produce natural-language proofs is a deliberate constraint that makes outputs auditable, which matters most in safety-critical and regulated domains. OpenAI has been circling adjacent territory with its reasoning models, and the competitive pressure to own the formal verification layer is real, even if neither company has framed it that way publicly.

Watch whether DeepMind publishes a reproducibility package or benchmark suite that lets outside teams validate the 2.5 percent success rate on a standardized Erdős problem set. If that drops within six months and the rate holds, the cost-per-proof figure becomes a credible procurement benchmark; if it doesn't ship, the headline number stays a one-time demonstration.