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turbobutton • today at 11:46 AM • 6 replies • view on HN

I believe there's a hard distinction between abstract, mathematical correctness in software and functioning in the real world. Any software that's processing inputs and provides complex workflows to humans has to necessarily deal with the endless vagaries of reality.

That's not to say there isn't value in formal correctness, but the important part is identifying when it's useful and when its more trouble than its worth...


Replies

kodoman • today at 12:44 PM

For me it seems more like modern software has built away from using formal mathematical models in the first place, not the necessarily the problem people want to solve have to have such a fuzzy definition of domain, but that the primitives of operating systems and software development have gone in the other direction.

Think about the filesystem, the big issue with formalizing a program spec that operates on a file system is simply the fact it is essentially a shared object amongst all the programs running on the system. Add to that the fact that (though this changes with modern containerization systems, namespaces, pledge what ever) a program may at any point gain access to root permissions if it makes the system call to do so providing the correct credentials it becomes very difficult formally be able to remove any possible states from the system.

All this could be different but we would radically need to redesign are systems and the way we think about the problems.

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xpct • today at 12:34 PM

What I've learned this year is that we should be verifying the fridges..

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darkwi11ow • today at 12:10 PM

I agree with you that for most software, verification was historically less of the requirement, however some software always needed to have abstract, mathematical correctness -- think military, medical, industrial automation.

While these areas were main premise of an article when it was written, I think the article really aged well into current time of mass AI/LLM deployment. It shows fundamental limitations of token based systems / symbolic reasoning that LLM espouses internally, while writing correct software. These limitations also apply to humans, however humans mental modelling, being not fully based on symbolic processing, have been historically shown capable of writing correct software systems, while AI/LLM systems have not been proven to be able to do that, and as article shows that with current token based technology it's unlikely they will ever be.

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ekidd • today at 12:07 PM

There is a wide range of software that exists in a "adversarial" environment, including anything facing a network or processing outside data. At a minimum, this software should should not allow an attacker to execute code of their choice on a system handling private data.

This does not require proving systems complete correct, but it does involve proving many properties of these systems.

fsloth • today at 12:47 PM

You can combine both sometimes in application logic.

Some API:s can be perfect. But then the real world adaptation needs to happen inside the module serving the API.

turbobutton • today at 11:53 AM

Having been downvoted, I like to clarify that this comes from the experience working in finance with developers with a strong academic background that emphasized on the necessity of formal proof to a point where complexity made actual progress nearly impossible- while simultaneously basing the proof repeatedly on assumptions that did not uphold in practice.

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