Didn't some of the recent proofs exploited a couple of blind spots of lean, and they were invalidated?
Edit: Yup. A bug report to Lean was disguised as a "Collatz" proof in a humorous way. Links below.
Didn't some of the recent proofs exploited a couple of blind spots of lean, and they were invalidated?
Edit: Yup. A bug report to Lean was disguised as a "Collatz" proof in a humorous way. Links below.
There was a hash collision bug in the main Lean kernel that was patched, but AFAIK nothing relied on it. You'd have to know what you were doing to accidentally get there...
The incident in the links I posted exploited several bugs AFAICS, so it's a different story than a single hash collision bug, it seems.
I don't know ... do you have a reference?
Yup, found it:
https://news.ycombinator.com/item?id=49101465
Cool, thanks!