Tiny Pickles: Why are AI companies investing so much in math proofs?

The essay uses OpenAI's September 2026 announcement of an AI-discovered analytical result on the Navier-Stokes equations as a starting point to explore why formal proofs matter for AI and software. It traces Gherkin and Cucumber's readable test language, spec-driven development from 2004, and Anthropic's Frontier Red Team work on LLM-assisted formal verification, noting that verifying the seL4 kernel took 20 person-years versus two to implement.