Team completes Lean formalization of Thurston geometrization conjecture in 4.7M lines
A team led by Princeton scholar Ayush Khaitan, working with NVIDIA's Humanfia team, says it has completed a full Lean formalization of the Thurston geometrization conjecture. The project spans roughly 4.7 million lines of code, about 2.7 million of which were added in around two weeks on top of roughly 2 million lines of prior work by Chow, Liao and Qin, and it has been open-sourced on GitHub. The team includes Bennett Chow, a Yau Shing-Tung student and UC San Diego professor, plus formalization leads Ziyang Qin and Yuan Liao; Stanford mathematician Jared Duker Lichtman publicly called the work amazing. The report notes that the geometrization conjecture is broader than the Poincaré conjecture, which Perelman proved as a byproduct, but NVIDIA has not disclosed the details of AI's role, and much of the article's account is inference.
If the formalization is as complete as described, this machine-checked differential geometry library could be reused in later mathematical work and signals how large models plus proof assistants might handle advanced geometric reasoning.