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  LightMachine
  Hi, I'm the author.HN staff: someone posted before me. Could we change the title to "Bend - a language that blocks AI mistakes via proof and runs on GPUs"?Everyone: feel free to ask any question, but I'd be highly appreciative if you could be a bit civilized and respectful this time. I've worked on this for 1 year, nearly 16h/day, 7 days a week, and I'm giving it for free. You need not to use it. So, I'd be thankful if you could point occasional failures politely rather than throwing me in a lava pit.Thank you!
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  svachalek
  Cool idea. I tried using it to port a little meeting fixer cron job I vibe coded, it seemed a natural fit as its essentially trying to satisfy invariants in my calendar.It basically succeeded but Claude (Opus 5) did have some complaints:'Base ships one arithmetic law, U32.add_comm. There is no order theory. About 60 of PROOF.bend's 163 lines are cmp_refl, and_false, and_comm, le_max_l, le_max_r, add_succ — facts you'd assume exist. You'd write them once per project and never again, but budget for them.''Base's Nat.max is unusable in a proof. It's Bool.pick(Nat, Nat.is_lt(a,b), b, a), and a proof can't case on a computed value. I wrote a structurally recursive nat_max so it unfolds in lockstep with Nat.cmp.''The law I most wanted: "no two output plans overlap." I didn't state it. It needs the sortedness of collapse's input as a hypothesis, and Base's List.sort ships no sortedness law — so getting there means proving merge sort correct first. That's the honest measure of the gap between "provable in principle" and "provable this afternoon."'I've got basically a minor in CS so I'm a dummy when it comes to proofs. I don't know if this is valuable feedback or simply Claude misunderstanding something.
• chaidhat
  I think this is premise for AI: Lean and formal verification seems more and more important in today's world and I think a variation of programming language like this is bound to win. This, or a library or framework to prove typescript.
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  RomanKornev
  > LAWS.bendI like the law idea, but what i found they end up doing is they just modify the law itself to fit the new feature they are working on, which defeats the point.Which means some laws needs to be frozen. But not all laws, otherwise you can't add or modify anything. So the judgement is still on the human part, and we're back to meatbags being the bottleneck.I've seen some success adding these proof-like checks to CI every time agents do something irrational. I definitely think it should be part of every codebase.There's also https://code-contracts.cc/ which co-locates code and proofs together.
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  garrisonj
  The issue is I’ll have to vibecode all the laws and the laws could be wrong.
• gkfasdfasdf
  But how does it do on the balls benchmark???https://benjdd.com/languages/
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  tyushk
  Victor Taelin's work (HVM) got me interested in interaction combinators as a compilation target. I'm now working on an implementation as part of my Uni research. Cool to see Bend 2.0 release!
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  jwpapi
  I’m missing an actual explanation of how that works.I feel like we all had the idea, but how is all possible move sequences proven ?What if the possible scenarios are too big to proof or test.Like on a 2 dimensional game it’s easy, but you could make it multidimensional and introduce an unlimited amount of special rules, (if on a prime number dimension on 3 but not more prime numbers you are allowed to jump to another prime numbers with 3 but not less coordinates)How is bend protecting it? I was checkin github and the paper, but I was not motivated enough. I feel like an actual explanation of how proofing works is missing.For Lean I understand how it works, here not.
• hollowturtle
  Would the author have specified on the page that it's a fast new language with a new take on proof and so on, without mentioning ai and that alone would have caught my attention. It seems like if there isn't the word ai people are not interested anymore, we used to care many of us used to care
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  hmokiguess
  So sad that commit history is a thing we can feel emotionally attached to a point of feeling vulnerable when releasing it with others.Also equally sad that without a way to relate easily with how something came to be (e.g. the commit history) others will struggle focusing at the work and will judge its lineage.I guess to folks here confused by that go search SrPeixinho on Reddit and that should have a lot of history for you to understand the background of the work, and you can also join their Discord server and literally talk to them there.
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  docheinestages
  Unless the proofs themselves are defined with natural language, I don't see them being adopted by humans. It takes a high cognitive load to read let alone write a proof.
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  stschaef
  This reads very vibecoded, but putting that aside...1. How does this benefit from GPU parallelism? I don't know much about implementing proof assistant, as I am just a user, but its my understanding that these tasks aren't amenable to running on a GPU.2. The comparison to Lean/Agda/Isabelle/etc have no meaning without understanding what programs are being used for comparison. I also so far have no reason to believe large-scale verified programs would ever adapt to Bend. For instance, I have a large software verification project written in Cubical Agda https://github.com/um-catlab/cubical-categorical-logic it's not clear to me how one would even begin to port this over to Bend, especially given the dependence on cubical3. Single commit history is hella sus4. Bend uses "an affine dependent type theory". Substructural dependent type systems are an active area of research. If this weren't slop, I'd expect such a system to be worthy of publication at a top programming languages conference. It sounds quite unlikely that a random vibecoded project with a Fable-written paper has worked out all of the kinks5. I would've at least expected this paper to be cited https://arxiv.org/abs/2401.15258 but it is noticeably absentI'm glad you're having fun vibecoding, and I like that you're interested in this area of research/engineering, but you are wildly overstating what you have here and sound sus af
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  pron
  > In the post-AGI economy, humans will eventually stop writing and reading code, but we still need an ambiguity-free way to tell the AIs building the world around us what we want done.Why? Won't an AI that can correctly write any program (and make any change) also be smart enough to know what exactly we want better than we can explain, at least ahead-of-time?If AGI means "human level", why is there any part of the process that humans will be needed for, especially some engineering aspect?> With proofs, we can verify that the AI implemented our prompts correctly.Certainly such an AI would be able to just write machine code directly and verify it through whatever means, including formal proofs, as needed. Why does it need a compiler?I think that an AI that's smart enough to write almost any program and prove almost any property, will also be smart enough to not need to communicate with us formally and rather answer every question we have (and proofs are not always necessary, as they're not always necessary today), and probably also smart enough to figure out what we want built. It's probably capable enough to replace the software's users, too. I don't understand why it's likely that we'll have AI that's so capable to write all software correctly, yet not capable enough to do things that are probably easier.
• fudged71
  Congrats on the launch!Question, does the parallelism work on M-Series GPU? The page says CUDA parallelism but shows Mac performance numbers.
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  whoamii
  “but we still need an ambiguity-free way to tell the AIs building the world around us what we want done”Do we? I would argue one of the main reasons AI can be so productive is because it makes assumptions where it finds ambiguity, and we reduce the number of things we need to specify.
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  Dwedit
  You just need to split apart "Wall is stop".
• emagdnim2100
  have been following bend's development via x for some time - congratulations on the release!
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  giancarlostoro
  Weird claim about us living in a post-AGI world, no company has shown true AGI yet.
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  amluto
  Maybe in our brave new world only the "laws" will matter and the implementation language is irrelevant to humans. In the mean time I have some questions about the "guide", which claims to define the entire language:https://github.com/bendlang/bend/blob/main/guide/GUIDE.mdLet's see:- There are no infinite loops, and recursion is kind of softly bounded to 2^48-1. This sounds grrrreat for games. I guess they have to stop working after a while? (What would be wrong with addressing this conceptually like Lean does? Have a way to annotate a term as possibly non-terminating?)- We seem to have Data and Type and Kind, and they don't mean what they conventionally do. '-' means "used 0 types". And the example is: def length(a, -A: Kind(a), xs: List<a, A>) -> Nat: match xs: case Nil{}: 0n case Con{h, t}: 1n+length(a, A, t) But wait! A is used albeit not at runtime. Is it possible that this actually intends "A may be used any number of times and is itself the name of a - type"? Shouldn't that be spelled "A: Kind(a) & -" or similar? Why does the kind even matter for this example?- I don't understand the Array example: import Base def main() -> Array<U32> & U32: a = [0 : U32*8n] # new array with 8 copies of 0 a[5] <- 42 # performs an in-place rewrite a[5] # reads index 5 What is the return type of this function? It looks like it returns U32. So what's "Array<U32> & U32"?- I don't even understand the Array explanation:> The slot count after * is a power of two; [0 : U32^3n] names the depth instead.Okay, the 8 in *8n above is indeed a power of two. Does the language require it? Does it actually mean 2^8? What is the "depth" of an array? Does this language not have non-power-of-two-sized arrays?At this point I stopped reading.
• daishi55
  Hmmm. I don’t really have any issues with frontier models not implementing my prompts correctly, and presumably that will only become more and more the case as the models get better and better. This seems like almost a non-issue already and certainly on its way to becoming one for sure?
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  AlexErrant
  https://github.com/bendlang/bend...did they just squash the repo to 1 commit for v2.0.4? Why? Yall should know that in this age of AI trust is the real currency... and nuking your history is one hell of a way to raise eyebrows.> Enjoy bug-free, fast vibe-coded apps! Hints: ask it to write laws for whatever should never break, and to parallelize everything you want running fast. Bend is young: if anything goes wrong, ask it to open an issue.Emphasis mine. I don't want to be snarky but like... come on.
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  lr0
  How is that better than just writing tests and running them in any other language, let's say Go?
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  anon
  undefined
• v9v
  I'd like to hear how this compares to Ada/SPARK.
• npn
  I read the readme and the guide file. There is just one thing I can comment: might as well solve the NP hard problems. I think you can do it easily, author. As you can already solved harder problems than those with your language.
• monster_truck
  No windows? axiomatic F32? I'll stick with Slopjective-C 3.0 thanks
• hirako2000
  Great team behind it. SSL cert is quantum resistant even.
• anon
  undefined
• resonious
  Sick of seeing "vibecoded!!" in the comments. It is an AI-oriented tool. Do you expect the author to write everything by hand? Do you think a couple of Claudeisms in the docs means the entire thing is unsupervised slop?
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  mantovanidaniel
  .
• gigatexal
  All these skeptics and nobody just tried it out?I will later. From what I can tell it looks nice. I like the syntax. I don’t know of the claims but willing to give it a shot.The GPU story would it work on my Mac or is it not GPU agnostic?
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  12uq7
  claude: 1 commit 1,722,119 ++0 -- I assume that Claude formally proved Bend correct like CakeML?Why would anyone want to work with such a dystopian setup? Prove your code directly in Lean or Coq or leave it.
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  bb-connor
  20k stars is sooooooooo sus lmao
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  IshKebab
  Interesting... But I don't think formal software verification is going to be the answer (is that what this is? Kind of unclear.)It's too difficult and doesn't scale well to many real world programs - how do you formally verify Facebook?We'll probably be stuck with normal testing and at least skimming code for a while.
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  boxed
  A single commit in github, and the compiler isn't there anyway. Where is the compiler?
• kevinbaiv
  [flagged]
• brcmthrowaway
  [dead]