Curious if anyone else had the same reaction as me This model is specifically trained on this task and significantly[1] underperforms opus. Opus costs about 6x more. Which seems... totally worth it based on the task at hand. [1]: based on the total spread of tested models
Leanstral: Open-source agent for trustworthy coding and formal proof engineering
101–110 of 234 posts
Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering
#102Curious if anyone else had the same reaction as me This model is specifically trained on this task and significantly[1] underperforms opus. Opus costs about 6x more. Which seems... totally worth it based on the task at hand. [1]: based on the total spread of tested models
Agreed. The idea is nice and honorable. At the same time, if AI has been proving one thing, it's that quality usually reigns over control and trust (except for some sensitive sectors and applications). Of course it's less capital-intense, so makes sense for a comparably little EU startup to focus on that niche. Likely won't spin the top line needle much, though, for the reasons stated.
Most Copilot customers use Copilot because Microsoft has been able to pinky promise some level of control for their sensitive data. That's why many don't get to use Claude or Codex or Mistral directly at work and instead are forced through their lobotomised Copilot flavours.
Remember, as of yet, companies haven't been able to actually measure the value of LLMs ... so it's all in the hands of Legal to choose which models you can use based on marketing and big words.
Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering
#103Curious if anyone else had the same reaction as me This model is specifically trained on this task and significantly[1] underperforms opus. Opus costs about 6x more. Which seems... totally worth it based on the task at hand. [1]: based on the total spread of tested models
But you can run this model for free on a common battery powered laptop sitting on your laps without cooking your legs.
Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering
#104Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering
#105Earlier quoted context omitted.
Presumably the idea is that an agent generates a Lean4 specification against which the software is measured. But then the Lean4 specification effectively becomes the software artifact. And we're sort of back to square 1. How do you verify a Lean4 spec is correct (and that it describes what needs to be built in the first place) without human review?
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Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering
#106Earlier quoted context omitted.
But you can run this model for free on a common battery powered laptop sitting on your laps without cooking your legs.
Sorry, but what are you talking about? This is a 120B-A6B model, which isn't runnable on any laptop except the most beefed up Macbooks, and then will certainly drain its battery and cook your legs.
I think it would still be fine for the legs and on battery for relatively short loads: https://www.notebookcheck.net/Apple-MacBook-Pro-M5-2025-revi...
But 40 degrees and 30W of heat is a bit more than comfortable if you run the agent continuously.
Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering
#107Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering
#108Earlier quoted context omitted.
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
#109Curious if anyone else had the same reaction as me This model is specifically trained on this task and significantly[1] underperforms opus. Opus costs about 6x more. Which seems... totally worth it based on the task at hand. [1]: based on the total spread of tested models
Agreed. The idea is nice and honorable. At the same time, if AI has been proving one thing, it's that quality usually reigns over control and trust (except for some sensitive sectors and applications). Of course it's less capital-intense, so makes sense for a comparably little EU startup to focus on that niche. Likely won't spin the top line needle much, though, for the reasons stated.
Re: Leanstral: Open-source agent for trustworthy coding and formal proof engineering
#110Trustworthy vibe coding. Much better than the other kind! Not sure I really understand the comparisons though. They emphasize the cost savings relative to Haiku, but Haiku kinda sucks at this task, and Leanstral is worse? If you're optimizing for correctness, why would "yeah it sucks but it's 10 times cheaper" be relevant? Or am I misunderstanding something? On the promising side, Opus doesn't look great at this benc…
I do like agents (like Claude Code), but I don't consider myself to be vibe coding when I use them. Either I'm using a language/framework I know and check every step. OR I'm learning, checking every step and asking for explanations.
I tried vibe coding, and really dislike the feeling I have when doing it. It feels like building a house, but without caring about it, and just using whatever tech. Sure I may have moisture problems later, but it's a throwaway house anyway. That's how I feel about it. Maybe I have a wrong definition.
Maybe it's good to not use "vibe coding" as a synonym for programming with agent assistance. Just to protect our profession. Like: "Ah you're vibing" (because you have Claude Code open), "No, I'm using CC to essentially type faster and prevent syntax errors and get better test coverage, maybe to get some smart solutions without deep research. But I understand and vouch for every loc here. 'We are not the same.'"