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Leanstral: Open-source agent for trustworthy coding and formal proof engineering

mistral.ai

81–90 of 234 posts

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#81
post #78

Congratulations on the launch! Mistral seems to focus on a different market than the others. Their best model is meh, their best ASR model locally is either rather slow compared to Parakeet on similar languages, or not as good for others (like qwen ASR). Side note: Lean seems quite unreadable with tons of single letter variable names. Part of it is me being unaccustomed with it, but still.

Mistral seems to focus on some niche LLM model tooling that are somehow very needed in certain cases. Can't forget their OCR multimodal embedding model!

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#82
post #74

It’s great to see this pattern of people realising that agents can specify the desired behavior then write code to conform to the specs. TDD, verification, whatever your tool; verification suites of all sorts accrue over time into a very detailed repository of documentation of how things are supposed to work that, being executable, puts zero tokens in the context when the code is correct. It’s more powerful than ream…

AI is the reality that TDD never before had the opportunity to live up to

Not just TDD. Amazon, for instance, is heading towards something between TDD and lightweight formal methods.

They are embracing property-based specifications and testing à la Haskell's QuickCheck: https://kiro.dev

Then, already in formal methods territory, refinement types (e.g. Dafny, Liquid Haskell) are great and less complex than dependent types (e.g. Lean, Agda).

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#83

I absolutely called this a couple of weeks ago, nice to be vindicated! > I'm interested to see what it is in the age of LLMs or similar future tools. I suspect a future phase change might be towards disregarding how easy it is for humans to work with the code and instead focus on provability, testing, perhaps combined with token efficiency. > Maybe Lean combined with Rust shrunk down to something that is very compile…

It's important to keep in mind that no proof system ensures your proof is the correct proof, only that it's a valid proof. Completely understanding what a proof proves is often nearly as difficult as understanding the program it's proving. Normally you benefit because the process of building a proof forces you to develop your understanding more fully.

Uhm, no? Even with "simple" examples like Dijkstra's shortest path, the spec is easier than the implementation. Maybe not for you, but try it out on an arbitrary 5-yr old. On the extreme end, you have results in maths, like Fermat's Last Theorem. Every teenager can understand the statement (certainly after 10 mins of explanation) but the proof is thousands of pages of super-specialized maths. It is a spectrum. For cryptography, compression, error-correction, databases, etc, the spec is often much simpler than the implementation.

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#85
post #84

Naturally the Microsoft-owned language is getting the AI hype instead of the more mature options that could do this sort of work… Agda, ATS, Coq/Rocq, Dafny, Fstar, Idris, Isabelle, Why3 just to name a few.

Am I missing something? Isn’t that the language most are using currently when looking at research at openai, google, deepseek etc?

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#86
post #60
post #23

The real world success they report reminds me of Simon Willison’s Red Green TDD: https://simonwillison.net/guides/agentic-engineering-pattern... > Instead of taking a stab in the dark, Leanstral rolled up its sleeves. It successfully built test code to recreate the failing environment and diagnosed the underlying issue with definitional equality. The model correctly identified that because def creates a rigid definit…

If Agent is writing the tests itself, does it offer better correctness guarantees than letting it write code and tests?

Given the issues with AWS with Kiro and Github, We already have just a few high-profile examples of what happens when AI is used at scale and even when you let it generate tests which is something you should absolutely not do.

Otherwise in some cases, you get this issue [0].

[0] https://sketch.dev/blog/our-first-outage-from-llm-written-co...

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#87
post #84

Naturally the Microsoft-owned language is getting the AI hype instead of the more mature options that could do this sort of work… Agda, ATS, Coq/Rocq, Dafny, Fstar, Idris, Isabelle, Why3 just to name a few.

A bit uncharitable. I'm a diehard fan of Rocq, but it's nothing unusual to see the young new hotness that is Lean continue to get the spotlight. It's not a sign of Microsoft putting its thumb on the scales, and the hype for Lean has long predated LLMs.

It's certainly less mature when it comes to verified programming, but its appeal to mathematicians (rather than formal methods experts) has earned it much respect.

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#88

Earlier quoted context omitted.

It's important to keep in mind that no proof system ensures your proof is the correct proof, only that it's a valid proof. Completely understanding what a proof proves is often nearly as difficult as understanding the program it's proving. Normally you benefit because the process of building a proof forces you to develop your understanding more fully.

Uhm, no? Even with "simple" examples like Dijkstra's shortest path, the spec is easier than the implementation. Maybe not for you, but try it out on an arbitrary 5-yr old. On the extreme end, you have results in maths, like Fermat's Last Theorem. Every teenager can understand the statement (certainly after 10 mins of explanation) but the proof is thousands of pages of super-specialized maths. It is a spectrum. For cr…

I don't know why you created a new account for this, but take the textbook example of a nontrivial formally verified system: SeL4. That implementation was 8.7k of C code, which correspondend to 15k lines of Isabelle that ultimately needed 100k+ lines of proof to satisfy. And that was with the formal model excluding lots of important properties like hardware failure that actual systems deal with.

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#89

Earlier quoted context omitted.

I don't think he's referring to Lean specifically, but any sort of executable testing methodology. It removes the human in the loop in the confidence assurance story, or at least greatly reduces their labor. You cannot ever get such assurance just by saying, "Well this model seems really smart to me!" At best, you would wind up with AI-Jim. (One way Lean or Rocq could help you directly, though, would be if you coded…

But isn't that tantamount with "his comment is a complete non-sequitor"?

I don't think so? Lean is formal methods, so it makes sense to discuss the boons of formal and semiformal methods more generally.

I used to think that the only way we would be able to trust AI output would be by leaning heavily into proof-carrying code, but I've come to appreciate the other approaches as well.

Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering

#90
post #48

Earlier quoted context omitted.

EU could help them very much if they would start enforcing the Laws, so that no US Company can process European data, due to the Americans not willing to budge on Cloud Act. That would also help to reduce our dependency on American Hyperscalers, which is much needed given how untrustworthy the US is right now. (And also hostile towards Europe as their new security strategy lays out)

This would be unfortunately a rather nuclear option due to the continent’s insane reliance on technology that breaks its unenforced laws.

How about not making these unenforced laws in the first place so that European companies could actually have a chance at competing? We're going to suffer the externalities of AI either way, but at least there would be a chance that a European company could be relevant.

The AI Act absolutely befuddled me. How could you release relatively strict regulation for a technology that isn't really being used yet and is in the early stages of development? How did they not foresee this kneecapping AI investment and development in Europe? If I were a tinfoil hat wearer I'd probably say that this was intentional sabotage, because this was such an obvious consequence.

Mistral is great, but they haven't kept up with Qwen (at least with Mistral Small 4). Leanstral seems interesting, so we'll have to see how it does.

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