falso

Ah, I should have clarified that. Yes, if stack overflow resulted in a trap you are mostly okay, given that the caller is eventually able to recover from the trap. But imagine that the trap didn't happen because the page table wasn't configured, like in the kernel context. Now your program will venture into some unintended memory region, yikes! But that was about the general language-based security, and you are correct that this particular case wouldn't matter much for Cargo. I only used this example in order to show that fully verifying language-based security is very hard in general. Even Coq, a well-known proof verifier with a solid type theory and implementation, suffered from some bug that allowed `false` to be proved [1]. It's just that hard---not really feasible. [1] https://github.com/clarus/falso

I would consider a proof to be a "repeatable argument". One you could show to someone and expect them to be convinced by it. I think it is a defensible viewpoint that a proof in coq is not 100% convincing. If you think otherwise, then how can you reconcile the existence of falso (a coq verified proof of "false")? https://github.com/clarus/falso Proof and belief I think are pretty strongly intertwined, but I'm not going to pretend to have a particularly rigorous philosophy on the matter. Similarly, when the proof of Fermat's last theorem was published, I don't know if I should consider that to be a proof because it is well beyond my comprehension. I have no reason to question it, but should I consider it a proof? I know that people smarter than me (e.g. Wiles) thought the original version of it was a proof, but it had a subtle error in it

Fun fact: even theorem provers have counterexamples - Breaking Badfny: https://www.reddit.com/r/Coq/comments/x4d31y/breaking_badfny... - Falso (Coq): https://github.com/clarus/falso - Coq critical bugs (some of these mention potential ways to prove false): https://github.com/coq/coq/blob/master/dev/doc/critical-bugs (You can also get the theorem prover itself to hang or crash; if you work with theorem provers often, you'll even do this unintentionally, many times!)

I believe this comment is meant to be a response to another post (https://news.ycombinator.com/item?id=18155410) who pointed out a flaw (now fixed) in Coq that allowed false theorems to be proved. Github link: https://github.com/clarus/falso

Even coq have had its bugs where it was possible to prove that true is false: https://github.com/clarus/falso

Is the Coq bug you're thinking of this one, from earlier this year? https://github.com/clarus/falso