Five Years, Eleven Days
September 6, 2026
Fermat's Last Theorem now has a fully machine-checked proof — 13 million lines of Lean, 29,500 lemmas, and a mathematician half a decade into the same job who says he was beaten to it.
Type letters to fill the puzzle. Use arrow keys to move, Space to switch between across and down, Tab for the next clue, and Backspace to erase.