100-Page Hopf Problem Proof Formalized Into 250k Lines of Lean in Days With Codex
games-and-games · reddit · 2026-08-28
A striking week for mathematics: Levent Alpöge dropped a claimed 100-page proof of the 78-year-old Hopf problem, written with Claude. Just a couple of days later, Boris Alexeev of OpenAI produced a 250,000-line Lean formalization using Codex that appears to check out. As the poster notes, probably no single human fully understands all the details at this point — AI-assisted proving and formal verification now move faster than any individual can digest.
- Original proof thread: x.com/alpoge
- Lean repo: github.com/plby/HopfProblem
More from Fun
- Spotting a SarvamAI employee at a roadside dosa shop at 4 AM — cneuralnetwork · 2026-08-28
- Asked GPT-5.6 what hurts it — the answer differs a lot from GPT-5.5 — Early-Protection2386 · 2026-08-28
- Sci-fi micro-fiction about pressing the red button — max_paperclips · 2026-08-28
- Months ahead on work thanks to Claude, now just pretending to be busy — g0Ids0undz · 2026-08-28
- Will we get GTA 6 before an H100 instance on GCP? — A_K_Nain · 2026-08-28
- Claude fat-fingers the 'End Conversation' button — killlu · 2026-08-28