Classification of Finite Simple Groups Formalized in Lean

13 hours ago (cfsg.axiommath.ai)

Out of curiosity: is it possible to take a frontier model and just let it loose on all math textbooks out there, converting each and every proof/theorem/lemma/etc. into Lean? A frontier model should be able to do that, right? And it's a one-time task: do it once and it's there for eternity, available as a library to be used in other proofs.

Maybe my understanding of Lean is wrong; I'm thinking of it as a programming language but for Math.

  • Axiom MTS here. What you describe is pretty close to how we formalised this proof, which is scattered across more than 500 articles and books: a swarm of agents was tasked with going through all these sources.

    One challenge is assembling everything into a coherent whole, since the same informal concept can be formalised in slightly different but incompatible ways.

  • Yes, but thing is, for a lot of basic stuff there are myriad ways in which it is formulated, so humans have to decide which of them goes in the library. Of course you can include two or five or ten equivalent formulations (like textbooks sometimes do) but still, not everything under the sun.

    Probably this will be done in some form in the coming months.

    • The really interesting aspect of this, IMHO, is discovering what theorem formulations combine together well as a whole. It's much akin to a software architecture problem.

      Metamath has done quite a bit or primary research into this. Theorems often have a slightly non-standard, but more general form.

      One can ask things like, "what is the equivalent of functional programming?" Or, "is there global state?" It's a perspective on reverse mathematics.

    • > Of course you can include two or five or ten equivalent formulations (like textbooks sometimes do) but still, not everything under the sun.

      Note that mathlib currently includes duplicates of many theorems; I believe deduplication is an active goal (if not one seeing much labor right now).

  • I think people assume that it would end up not being usable by humans without a lot of hand-holding. Though maybe that's wrong, and somebody should try it.

This seems like a very good use of auto-formalization, because in the past mathematicians have incorrectly believed that they were finished with the classification only discover a missing class/sporadic group.

The original proof was a collaboration of ~100 mathematicians, if Tao is correct then we should expect to see more such collaborations in the future like we do in e.g. physics.

  • They didn't discover a missing sporadic group. The big gap in the proof (the quasithin case) happened because it was covered in a 600-page unpublished manuscript that under further investigation turned out to be incomplete.

Makes me sad that the homotopical foundation people never got their shit together and now formalization is so mature but it's still done in set theoretic foundations.

  • Last week I blew my whole Claude Max weekly budget having Opus translate from Mathlib to Coq-HoTT. It was so beautiful I can't wait to do it again this week.

  • No Type Theory won: Per Martin-Löf is still alive and should be able to confirm his work lives in some form in Lean. Zermelo and Fraenkel would be utterly confused, however.

    What you mean it say is that Lean is not a HoTT, and Mathlib has tons of classical reasoning (excluded middle, axiom of choice).

    I don't think it's too late at all for HoTT. In fact, I think the AI companies will find trying to crank out more new math which is out of distribution in a funky way a highly useful exercise.

  • Hey now... If you have a formulation in type theory (lean is not set theory), then you can translate to homotopy type theory fairly easily

Groups were my gateway drug into abstract algebra. A friend clued me into symmetry being everywhere and Groups are how symmetry is formalized, and it’s been a crazy journey understanding all that. The frontier models can tie those abstract concepts to plain English examples and answer questions decently well, it’s never been a better time to pick up the field solo and see what it has to offer us

Filling in well-known gaps like this is the kind of thing the AI companies should be doing, not trying to scoop research in progress.

The formalization is 43.1M lines of Lean.

Note they found one gap (and filled it) in the previously accepted 1,000+ page proof. So that's pretty cool.

LLM formalization is not as useful as human formalization, but nice to know that the Classification is correct

Page has some kind of redirect bug that steals the back button, may want to open it in a new tab to avoid that.

I'm surprised they only found one gap. I would have expected multiple (fixable) gaps would have been uncovered, especially since the result was spread over many papers by many different people.

Looking at the visualizations made me wonder if the embeddings themselves can be used to suggest, if not derive, mathematical results. I realize it depends on the quality of the embeddings.