I could prove anything by claiming I completed a trivial-to-explain exhaustive search. The only support or refutation would be someone doing their own search. It's a very weak foundation.
We already had the ABC conjecture crisis: A theorem with a human-written proof so complex that no one besides the author can understand it. Some people claim to have refuted it. Most mathematicians are unqualified to decide.
Hmm, doesn't it take an expert to explain why those cases are exhaustive, and why the code that checked them is correct?
Tangentially, I'm not a mathematician but I wonder if one "opaque" proof that is too complicated for anyone to understand, but that we know is correct via formal verification, might end up being built on with "transparent" human-understandable proofs. For example, it's my understanding that there are many conjectures that have been proven true conditional on the riemann hypothesis being true. In that case, an opaque proof of the riemann hypothesis would enable those conjectures to be known and built upon
To your first point. There a large number of cases that maps can be reduced to. Very few people have checked these reductions themselves. In 50 years there will be no human alive that will have checked the reductions by hand. Do we then discard the theorem? More importantly, do we trust the people that claim to have checked all the reductions? There are hundreds of cases. I trust a computer verification much more than I’d trust human verification. Humans will likely make mistakes due to the tedium. And some will claim understanding of all cases but be wrong in their understanding in some of the cases.
Just burn lots of tokens on the frontier model of your choice to let the AI find a high-level argument why the four color theorem holds. :-)
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Seriously: since there exist quite a lot of readers on HN who are both hardcore into AI and mathematical problems: This is a challenge for you.
I am looking forward to seeing an announcement of a novel high-level argument why the four color theorem holds on the first page of HN in at most a month. :-D
But the point is that pre-AI it was already the case that famous results were published that very few could understand or digest. I think it is reasonable to expect that we will soon be at a point that Lean says a theorem is correct but no human can or will ever understand the proof.
What if Lean verifies Mochizuki’s proof of the ABC conjecture. Do we disregard it becuase no other mathematician understands the proof?