ComplexSystems
6 days ago
Aside from the usual squabbling about AI, it seems the bombshell claim is this:
"In particular, we show that the formalised Lean proof does not correspond to the NL proof of blow-up of solutions to the Navier-Stokes equations."
So these authors seem to be claiming that OpenAI has not really proven Navier-Stokes at all. If I get their idea correctly, they are claiming that the LLM has not formalized the original "natural language" idea of Navier-Stokes correctly. If true, it would mean that their purported Lean proof is not actually a proof of Navier-Stokes at all, but something that is an incorrect translation of the original natural language idea. If correct, this is a really bold claim and I would like to see if other researchers agree.
mkarrmann
6 days ago
No, they're not claiming that.
No one is disputing that the Lean formaization of Navier-Stokes is correct, so we should have high confidence that the generated Lean proof is valid.
The authors are claiming that the Lean proof is not the same proof as the NL one. Therefore, we shouldn't yet have confidence that the NL proof is valid.
This is an important claim which the math community will need to work through. However, the Lean proof alone is sufficient for OpenAI to (reasonably confidently, leaving aside questions of academic manners) claim to have proven NS.
nayroclade
6 days ago
So, the AI wrote a NL proof of Navier-Stokes, then incorrectly auto-formalised it to Lean, but still ended up with a verifiable proof of Navier-Stokes? That seems... strange?
traes
6 days ago
This same thing happened back in the 10 advances in math and CS release a month or two ago. The non sofic group construction relied on false prior literature. They realized this and fixed it in the lean program but didn't modify it in the writeup, so the written proof was both incorrect as stated and did not correspond to the lean proof. I was surprised how little press it got at the time, it seems like a huge risk factor.
latent-person
6 days ago
Or the AI wrote a NL proof of Navier-Stokes, began rewrite in Lean, then discovered a false / handwavy / easier to write in Lean / etc approach of some parts of the proof, and modified it accordingly. Since there wasn't any backpass from Lean to NL to include any changes it did due to any of the above reasons, the proofs aren't identical. That's what I think is most likely.
If the reason for the differences was done intentionally in Lean (as opposed to hallucinate e.g. m+4 vs m+5 as mentioned in remark 3.2), then a simple recording of differences, and then afterwards pass back any changes to the original NL would fix the issue. If it was hallucinated, then there is no guarantee it wouldn't keep hallucinating, and thus you might never end up with the same proof no matter how many passes you do back and forth (see remark 3.4).
rtpg
6 days ago
I don't know if we can really be clear about the order of things, but I think even without AI maths is filled with "someone provides a proof of X, and the proof itself is wrong/incomplete but X itself is true".
"Incomplete" proofs might be a way of viewing this. You have a NL argument to prove X. It turns out the NL proof has holes you can drive a truck through. So... you go around and patch the holes.
The resulting proof is different! You can start off with a bad proof and find a correct proof. Sometimes.
EDIT: for French speakers (maybe autodub gets you there) I saw a very nice simple case of this recently. A commonly stated proof for a relatively simple theory. The proof has a giant hole in it, and completing it requires some work [0])
aidenn0
6 days ago
This happens all the time with human researchers.
e.g. one of the lemmas in the NL description is false, but a weaker version of the lemma (that does hold) is sufficient for the proof, so the (incorrect) lemma is never formalized.
famouswaffles
6 days ago
It's not actually the same model that solved the problem that did the translation. Astra did the translation after the intenral model produced the NL Proof. As for the discrepancies, It's not necessarily right to think of this as 'incorrect formalisation'. Maybe it was essentially a 'proof refactoring'. Maybe Astra thought some parts could be easier expressed in a certain way, or maybe aspects of the NL proof were kind of handwavey etc.
elcomet
6 days ago
Why do you assume this order? I would assume the AI starts with lean (that's what it was RL'd on at least) then tried to translate the proof for us humans, which is quite hard.
I'm not sure about it but it seems plausible given the potential error.
Edit: they explicite say that your order is correct in the post
rowanG077
6 days ago
I would expect it's the other way around. The AI wrote a Proof of NS in lean and write up a NL proof based on the lean one. The authors claim that openAI did NL -> Lean, but that is unsubstantiated.
vilhelm_s
6 days ago
The OpenAI announcement says
> The agents arrived at their resolution on Saturday, September 5, about 88 hours after the first agents were launched. Lean formalization and verification took an additional 17 hours via GPT‑6 Astra.
This seems pretty clear that they found the proof first and then mechanized it afterwards.
renyicircle
5 days ago
Proof steps can become different in Lean but still work to prove the theorem. Incorrect proof steps in the NL paper could also be converted to correct ones in Lean. The paper shows some examples of this. So the NL paper can't be trusted even if Lean verification passes, but it doesn't immediately mean that the NL proof is wrong or that Lean is checking the wrong thing.
persedes
6 days ago
Trying to map this observation to code and appreciate them starting with very simple examples (that Astra screw-fixed into lean.) But in a simplified way this is close to promting the model to create a set with the members 1,2,1,5 and it correctly creates {1,2,5} in code. So The initial "proof" / instruction was wrong and it silently fixed that. ( Which is one of the failure modes they're describing)
incognition
6 days ago
it's the result of thinking carefully about the translation process.
humans as a whole have always known the weakness of natural language is in its precision. In a way this isn't strange that this issue has come up.
nbulka
6 days ago
If you’ve tried any formalizing in codex Astra often works solely in Lean
runarberg
6 days ago
Or maybe the AI didn’t write Lean proof at all, or rather, not the LLM at least. But instead OpenAI has an internal traditional reinforcement model that is able to stumble on the Lean proof by the share amount of compute power available to them thousand monkeys on a thousand typewriter style. And then pretend LLM did it because that is what they are selling.
red75prime
6 days ago
You can't consider them monkeys if you need 1000 of them instead of 2^1000.
nbulka
6 days ago
Not necessarily monkeys but thinking in Lean first is quite plausible
famouswaffles
6 days ago
The mental gymnastics on display is amazing to see. You clearly have no idea of what you are talking about.
runarberg
6 days ago
I don’t. But I do know how the scientific method works, and OpenAI’s display is anything but. Until what they have demonstrated is reproduced I take their claims to be nothing but marketing. A for profit company will lie in order to maximize their profits. Above I presented an alternative hypothesis, which is probably wrong, but until OpenAI’s results are replicated I will believe my alternative hypothesis just as much as I believes the claims of the for profit company making them.
aesthesia
6 days ago
> I presented an alternative hypothesis, which is probably wrong, but until OpenAI’s results are replicated I will believe my alternative hypothesis
If you think it's probably wrong, why believe it?
runarberg
6 days ago
In the absence of evidence, a guess is the best you got.
And, no until OpenAI’s results have been replicated, I don‘t believe companies own words about their own products, and therefor a marketing statement is not evidence.
phoghed
6 days ago
I’m a non-math layman, and not a scientific method knower like yourself. How does one usually “replicate” a math or Lean proof?
krupan
6 days ago
It's the method they used to create the proof that's in question here. They claim their amazing product did it, and therefore you should buy their product because will do amazing things for you too!
runarberg
6 days ago
The generation of the proof can be replicated. And if it can‘t we should be suspicious of their claims.
bordercases
6 days ago
Hopefully not in the same way you should never naively trust compilers!
nyeah
6 days ago
>No one is disputing that the Lean formaization of Navier-Stokes is correct, so we should have high confidence that the generated Lean proof is valid.
These authors don't seem to be disputing that this Lean formalization of Navier-Stokes is correct. I don't think that gives us any new information about whether the generated Lean proof is or isn't a valid proof of this N-S blowup thing.
tempfile
5 days ago
> No one is disputing that the Lean formalization of Navier-Stokes is correct, so we should have high confidence that the generated Lean proof is valid.
Why? It is a correct proof. Is it a correct (dis-)proof of NS? These statements do not seem particularly related. People, including (especially?) mathematicians, find NL proofs far easier to read than Lean proofs. I would bet the ratio of people who read (part of) the NL proof vs the Lean proof is at least 100 to 1. It seems incredibly unlikely that anyone has read and reviewed the whole Lean proof (including the authors of the OP).
Is it particularly easy to see that the Lean proof does actually disprove NS, rather than proving something similar but not the same?
Ohentis
5 days ago
Well the theorum statement (what it proves) is short and easy to verify. I would not be surprised if hundreds of mathematicians have looked at it at this point.
measurablefunc
6 days ago
If it doesn't correspond to the original proof then you don't know what it is actually formalizing. It could be a buggy proof of ⊥.
aureianimus
6 days ago
The thing is that Navier-Stokes has a definition split off separate from the formalization, and that is what has been completed. People have looked at the definition of the final statement. This paper only mentions the proof and intermediate statement, not the final statement. The most likely case to me is that intermediate statements do not match, but the end result still holds.
measurablefunc
6 days ago
Seems kinda odd then that it didn't occur to OpenAI to iterate until they reached a fixedpoint for both the informal & formal development b/c it's obvious that correspondence should have been part of their training pipeline.
xigoi
6 days ago
Their aim was to create a correct-looking proof using as little resources as possible, not to create a correct proof.
auggierose
6 days ago
Jesus Christ, so many people here who have no clue what they are talking about.
A proof of a theorem is different from the statement of the theorem. OpenAI has a Lean proof of the statement. That is all they need. There may be many different proofs of this statement, including NL proofs. It does not matter that these NL proofs may or may not be different from the Lean proof, at least for the correctness of the Lean proof. But of course the NL proof may be wrong. But who cares?
aeternum
6 days ago
It reminds me of how provably secure software was all the rage for awhile. Until people found that the idealized system/lemmas were so far from reality that the proved security was worse than meaningless because it gave a false sense of security.
In order to prove security, you must first simulate the universe.
fn-mote
6 days ago
> the NL proof may be wrong. But who cares?
The people trying to understand the proof are probably following the natural language version. So they care.
I wouldn’t be surprised at all if that’s how this paper (which I did not read) arose.
utopcell
6 days ago
Why would they do that, knowing that the one known to be correct is the Lean one? Just to claim that the (correct) Lean proof did not translate well to English? That would be weak, and a colossal waste of energy and time.
akoboldfrying
6 days ago
Why do people program in Python instead of writing machine code?
Why are review papers published? Executive summaries? "Introduction to X" books?
People's time and computational resources are finite. Summarising information -- ideally in structured ways that preserve important properties, but even in informal, unstructured ways -- is critical for making any kind of progress in this world.
balaclava9
5 days ago
The statement written in Lean, is not actually a correct description of the Navier-Stokes problem. It's some other easier statement. That's why the Lean code may not be a proof.
Here's a quote from the paper.
"3.1. When the NL paper declares stronger statements than what Lean proves
We commence with an example that complements those in §2. In the following example the AI autoformalisation results in a different Lean proof of a weaker statement."
"Tracing the proof of (3.3) we find that the series arises from applying the Lean theorem coefficient_seminorm_bound, just as Figure 3 mentions. Consequently, the Lean results discussed in this section are weaker than (3.1) in the NL proof."
So the question is, was the Navier-Stokes problem framed properly in the lean code, or is some easier problem represented in the Lean code?
Here is their remark.
"Remark 3.4 (Further potential mistranslations of the Navier-Stokes proof). The above examples require careful manual checking of both the NL proof as well as the Lean proof, which is delicate and highly time consuming. Moreover, the fact that we display only two examples does not mean that these are the only cases of mistranslations."
vilhelm_s
5 days ago
The "statements" here are statements of lemmas, not the statement of the main theorem. The main theorem statement was written by humans (prior to the OpenAI work), so there shouldn't be any concern that an AI mistranslated it.
balaclava9
4 days ago
That could be that these examples are lemmas, but in the introduction the authors conclude,
"In all cases the correctness of the formal proof does not say anything about the correctness of the NL proof."
The Clay Mathematics Institute has not yet accepted the proof as it takes a while to review.
"The Clay Mathematics Institute is dedicated to furthering the beauty, power and universality of mathematical thought. Curating the Millennium Prize Problems is one of the most important ways in which it pursues this goal. The rules governing the prizes describe the process for evaluating what has been achieved and for assigning credit. The process is deliberately unhurried, but we will provide updates."
https://www.claymath.org/news/navier-stokes-announcement/
We can see therefore that we don't know if the OpenAI program wrote the NL statement or proof correctly. Or if maybe it needs work. Or if maybe it has significant errors.
We also don't know if Astra properly wrote the initial statement of Navier-Stokes correctly in Lean.
vilhelm_s
4 days ago
My point is that Astra did not write the statement of Navier-Stokes in Lean, there was already a human-written statement, so there should be no concern that it has errors.
This article shows that we can't conclude from the working Lean proof that the NL proof is also correct, because they are different in some places. On the other hand I think it's unlikely that it's "very" broken. OpenAI first spent a lot of computer time to find the NL proof, and then less time to translate it into Lean. So if there were errors in the NL proof it seems they were not fatal, the agent translating it into Lean was able to patch them up as it went along.
seanhunter
6 days ago
> Who cares?
Everyone. I don't think many people working in fluid dynamics were surprised you can find a blow-up in Navier-Stokes. What would advance human knowledge is understanding the situations in which a blow-up might occur. In that context, the lean proof is necessary, but the non-lean proof is more important.
ziiinq
6 days ago
> Jesus Christ, so many people here who have no clue what they are talking about.
Indeed. If only some of those people would see the irony.
What matters most of all, as any first year student of mathematics would know, is whether the formal problem statement corresponds to the NL statement. TFA specifically states that at least some of the allegedly proven formal statements DO NOT.
auggierose
6 days ago
No. What the paper says is that in principle, translating NL statements to Lean statements is hard. Nobody doubts that, translating informal to formal text cannot be formally proven correct, so...
Does the paper give a single example of one of the OpenAI solved theorems with a Lean certificate where the Lean statement does not correspond to the actual statement from the mathematical literature? I don't think so, but in case I am wrong, feel free to provide that example.
ziiinq
6 days ago
This is explicit in the abstract:
> To demonstrate the effect of this result we provide several examples of AI mistranslations of NL statements and proofs into Lean in practice, resulting in mismatches between NL proofs and their Lean ‘verifications’. These include OpenAI’s announced Navier-Stokes proof.
Could /I/ be mistranslating the paper’s formal statement to NL? I don’t think so, but in case I am wrong, feel free to cite the correct formal statement that they claim as divergent between Lean and NL formulations by OAI.
[edit: typo]
auggierose
6 days ago
Yes, you are misunderstanding what the paper claims. Navier Stokes for example is not such an example, only the proof is different. For their other examples, none of them they claim that they concern actually the open ai solved theorems. You are welcome.
ziiinq
6 days ago
you say that…
And yet I cited a specific statement made concerning N-S specifically, whereas all you’ve done is make patronizing remarks, and strawman arguments.
Have you actually read it? They give a handful of examples of mistranslations of both claims and proofs thereof, in relation to NS and Euler, though I do concede that they do not go as far as claiming outright the NS statement itself is mistranslated.
Unfortunately, lean proof alone is not enough. sidestepping the raging discussion regarding the meaning of mathematics, just because the lean compiles is not proof in itself that it is correct in the sense that mathematicians mean. Unless of course, you can prove that lean itself is correct, which you can’t.
we have seen “proofs” earlier this year that essentially abused some bugs in the kernel. it would be very convenient if every program written in rust was automatically correct if compiles - something i strongly suspect you believe - unfortunately, this is not the case for either.
latent-person
6 days ago
In case you are not aware, the actual theorem statement of N-S was never translated by an LLM, but was written independently by formal conjectures, as they say in the README [1].
A Lean proof has a much higher probability of being correct (in my opinion) than any published (either preprint or peer-reviewed) paper, yet no one before LLMs were walking around claiming every result published can't be trusted yet (without an actual reason).
We have seen one such instance of Lean bugs, which was found adversely against Lean (as in find bug then use this bug to prove Collatz, not just found when being asked to prove it).
It's also worth to note that the way N-S (and all the other proofs by OpenAI etc) have been found is first prove it in NL then translate to Lean. I.e. it would have to first believe it found a correct proof in NL, and then afterwards either accidentally or on purpose use a Lean kernel bug.
[1]: https://github.com/openai/NavierStokesAndEuler/blob/main/Com...
edit: Probably also worth to mention that the proof have been checked both by the Lean kernel and the independent nanoda kernel, so it would need to exploit bug(s) from both.
antonvs
5 days ago
> A Lean proof has a much higher probability of being correct
Define “correct” in this context. That’s the real problem here.
latent-person
5 days ago
Correct as in the Lean proof correctly finds a counterexample to N-S.
Here is what putting trust into a Lean proof means https://ammkrn.github.io/type_checking_in_lean4/trust/trust....
In particular the main ones are:
1. The theorem has been written correctly.
2. No exploit of a kernel soundness bug in Lean (and the independent kernel nanodo, which OpenAI also checks against).
In particular, if you trust this, then you don't need to care about anything else the Lean program does, no matter how many lines, lemmas etc. it makes along the way.
As I said above, the theorem statement have been written independently by formal conjectures, and you are free to read it yourself (or trust other people have done it).
So, assuming you don't disagree the theorem statement have been written correctly, you pretty much need to believe 2 is false, if you don't trust the proof [1]. And that's what I find has a rather low probability personally.
[1] As the book says, you also need to trust the hardware, firmware etc.
ziiinq
5 days ago
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ziiinq
5 days ago
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auggierose
6 days ago
Wow. You are exactly the person I am talking about in my original comment. Thank you for this illustration.
ziiinq
6 days ago
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balaclava9
5 days ago
You may be overconfident here. The NL paper may be properly stating the Navier Stokes problem, and the Lean code may not be.
Here's from the paper--
3.1. When the NL paper declares stronger statements than what Lean proves
We commence with an example that complements those in §2. In the following example the AI autoformalisation results in a different Lean proof of a weaker statement.
plepbpl
3 days ago
None of the examples are of the NS lean statement. The validity of the latter is not under question ( in this paper ). Please note the distinction between “statement of NS” and “statement of lemmas used in the NL proof of NS”.
bmitc
4 days ago
> The authors are claiming that the Lean proof is not the same proof as the NL one.
Is that exactly the same as saying the Lean proof isn't correct? I'm confused by what you're trying to distinguish.
hn_throwaway_99
4 days ago
No, it's the Lean proof that's correct, it's the natural language one that has the error.
bmitc
4 days ago
What has shown the Lean proof to be correct?
hn_throwaway_99
4 days ago
Lean is a theorem prover. If it "compiles", and the proposition as coded in Lean is equivalent to what the theorem proposes in natural language, the theorem is correct. https://en.wikipedia.org/wiki/Lean_(proof_assistant)
bmitc
3 days ago
I know what Lean is. That doesn't answer the question.
hn_throwaway_99
3 days ago
I don't understand then, because it doesn't sound like you understand how Lean works.
The actual proposition of the theorem is very short in Lean, and at this point has been looked at by probably hundreds of mathematicians (including the authors of the article). All that needs to be confirmed manually is that the proposition statement matches what people say the theorem actually proves. That has been done.
At that point, the rest of the actual proof steps are automatically verified by Lean - that's literally the entire point of Lean. There is no additional verification step - "What has shown the Lean proof to be correct" is the fact that the Lean program automatically validated it and generated a certificate.
But what mathematicians really care about is the actual steps. What the authors of the article have shown is just because you have a Lean program it doesn't mean the steps of the natural language theorem have been "autoformalized", because there is no guarantee the steps from the natural language description match the Lean code.
bmitc
3 days ago
A Lean program that compiles proves what it states. The question is whether the program states what we think it does. If I recall, this program is 12 million lines long. Mathlib is not perfect, and it's not hard at all to have a Lean statement that isn't what you think it is.
So my question is whether people have actually checked that the generated program, all 12 million lines of it, has the statements that are expected.
hn_throwaway_99
3 days ago
But that's where you're wrong. All 12 million lines do not need to be checked (again, that's literally the entire purpose of Lean). All that needs to be checked is that the proposition of the theorem is what we think it is, and that has been done. What Lean guarantees is that if you start with a set of axioms -> whole bunch of steps that nobody really ever needs to read -> final theorem proposition, that those steps do successfully prove the theorem.
You say "it's not hard to have a Lean statement that isn't what you think it is", and that's true - indeed, what the entire paper is about is that the intermediate steps in Lean don't match the natural language description. But the statement of the proof in Lean (which again is quite short) is what we think it is, and hence the Lean proof is valid.
bmitc
19 hours ago
> All 12 million lines do not need to be checked
That's extremely hard to believe. First, one question arises: what are the 12 million lines doing if they're not needed? Secondly, don't those 12 million lines build up the theory that is eventually proved? Mistakes could be there that makes the outer statement seem like something it isn't, could there not be?
dwohnitmok
11 hours ago
There's maybe an even simpler way of illustrating this.
Fermat's Last Theorem is very easy to state. There are no positive integers a, b, and c such that a^n + b^n = c^n. This likewise easy to write in Lean. The statement of the theorem is exactly one line of code.
theorem fermat_last_theorem (n : ℕ) (n_ge_3 : 3 ≤ n) (a b c : ℕ) (a_is_positive : 0 < a) (b_is_positive : 0 < b) (c_is_positive : 0 < c) : a ^ n + b ^ n ≠ c ^ n
Kevin Buzzard's team of human mathematicians attempted to prove this in Lean. They got to about 60000 lines of Lean code and were not anywhere close to finishing the job.Anthropic came around with a Claude model that proved it in 13 million lines of code. (Buzzard's team might have ultimately used within the same order of magnitude if they finished. It's very unclear. They were at minimum years away.)
Whether 60000 or 13 million, only one line of code was necessary to manually verify whether they had successfully proved Fermat's Last Theorem, just the statement of `fermat_last_theorem`. None of the rest of the code built up the theory at all.
Indeed if those lines of code built up the theory, that would suggest that the statement of Fermat's Last Theorem is incomprehensible, if professional mathematicians cannot define Fermat's Last Theorem in even 60000 lines of code! But that's pretty absurd. You can explain the statement of Fermat's Last Theorem, completely rigorously, to a middle schooler.
dwohnitmok
18 hours ago
> First, one question arises: what are the 12 million lines doing if they're not needed? Secondly, don't those 12 million lines build up the theory that is eventually proved? Mistakes could be there that makes the outer statement seem like something it isn't, could there not be?
This seems to reflect an incorrect understanding of formal mathematics.
Formal mathematics can be thought of as a game with rules where a statement to be proved is some game end state. If you play 12 million valid moves and arrive at the desired end state then you have proved that the statement is valid. If your logical system is sound (e.g. first order logic), then you have proved your statement is true.
The entire point of the formalization of logic and mathematics through the 19th and 20th centuries was to unlock this capability. Such that, if you only care about whether your statement is true or not and not why it's true, the intermediate steps are entirely unnecessary.
To answer each of your questions:
> First, one question arises: what are the 12 million lines doing if they're not needed?
They are the intermediate computations necessary to show that the final statement is valid. This is much like intermediate arithmetic operations in a large complicated arithmetic expression. As long as you believe that the computer can calculate each individual arithmetic expression correctly, you don't need to manually review the billions of intermediate calculations that result in the final number.
> Secondly, don't those 12 million lines build up the theory that is eventually proved?
No. Not in the way you're thinking of. It seems you are using "theory" to mean the concepts necessary to express the statement itself. This is a very different set of lines than the proof itself (and generally much much more compact). Very difficult to prove statements can be stated in very simple language. Often the theory is <0.01% of the total lines of code.
> Mistakes could be there that makes the outer statement seem like something it isn't, could there not be?
No. Only the language used in the final statement can cause this issue, i.e. the theory. The intermediate 12 million lines cannot affect this, assuming your computer can carry out arithmetic correctly.
Another way of thinking about it is that the big breakthrough of 19th and 20th century mathematical logic is to conclusively show that formal mathematics is fundamentally just a set of arithmetic operations.
Hence in a very real sense, proving a mathematical statement is exactly identical to finding x in an arithmetic expression f with some constant k such that f(x) = k, where k is determined by the statement you wish to prove (not the 12 million lines).
Showing that x causes f(x) to equal k is exactly equivalent to proving the mathematical statement associated with k.
The 12 million lines are an alternative notation, no different in spirit to decimal notation or binary notation, of writing down x. It is some gigantic natural number.
You must understand k. If you use the wrong k, then you have proved another statement than what you intended. This is usually about a dozen lines of code.
You must be confident in the correctness of f. This corresponds to the believing that your type checker (since Lean uses dependent typing as its method of proof checking) has no fundamental soundness bugs. This can be controversial and indeed Lean's type checker has had soundness bugs in the past! But crucially f does not depend on k or x. Every time you fix a bug in f you can rerun it for any k or x you care about.
But you don't have to actually read all the digits of x, in whatever notation you care about. You can copy paste it in from some gigantic file handed to you by a stranger. As long as f(x) = k, you know that you have proved the mathematical statement associated with k.
Overall, this is roughly like asking why you trust a computer to solve a long division problem that has 12 million intermediate steps if you don't actually read all 12 million intermediate steps yourself. Well I trust the computer to do one step of division correctly and to be able to repeat that faithfully 12 million times. Hence I trust the computer can solve a long division problem involving millions of digits, even if I don't actually look at all 12 million intermediate computations myself.
LelouBil
6 days ago
As an outsider to the field that what I understood from the person you are replying to. What's the difference ?
HWR_14
5 days ago
To put it in code terms.
1) The code and the comments disagree.
2) The code passes the tests.
3) The comments promise functionality the code does not implement.
The first post was "It doesn't meet the business requirements the comments indicated, so the software is broken." The replying post was "Actually, the business requirements were faithfully turned into tests, so the software is fine. The comments need to be rewritten"
baobabKoodaa
5 days ago
Also an outsider to the field and wondering the same thing. I can't see the difference. Can someone explain please?
Craftyawesome
5 days ago
They published both a natural language proof and a lean proof. This paper says the NL proof does not match does not match the lean proof, using different arguments and some stronger claims. It does not claim the lean formulation of NS or the rest of the lean proof is invalid.
"The Lean code merely tells us that the theorem is correct, yet the NL proof with intermediate arguments, lemmas and results may be incorrect or have incorrect arguments."
baobabKoodaa
4 days ago
You didn't answer the question. Quoting from upthread:
A: "In particular, we show that the formalised Lean proof does not correspond to the NL proof of blow-up of solutions to the Navier-Stokes equations."
B: "No, they're not claiming that [...] The authors are claiming that the Lean proof is not the same proof as the NL one"
The question was: what's the difference between A and B?
Your answer to that question was "This paper says the NL proof does not match does not match the lean proof".
It seems to me like A is the exact same thing as B, and you are here claiming that they're different things while merely repeating the same claim that was already claimed in both A and B.
Craftyawesome
4 days ago
Statement A is upthread quoting the paper, and is not the statement B is arguing against. B is arguing against the incorrect statement "So these authors seem to be claiming that OpenAI has not really proven Navier-Stokes at all."
mike_hearn
6 days ago
The English language description doesn't do the same thing as the code the AI wrote.
baobabKoodaa
5 days ago
This doesn't answer the question. The question was: what was the difference in A and B. Your answer looks like this:
A: The English language description doesn't do the same thing as the code the AI wrote.
B: The English language description doesn't do the same thing as the code the AI wrote.
A and B are the same; there is no difference. Is this what you meant? Or did you mean the opposite of this? If you meant the opposite of this, what exactly is the difference?
user
5 days ago
chadcmulligan
6 days ago
ie the code had bugs, and they didn't update the documentation. wouldn't be the first time.
isaacfrond
5 days ago
Which is exactly why you want a Lean proof in the first place!
NL proofs rely on not-entirely-correct prior art, and contain countless holes both big and small. When formalizing human NL proofs it is probably very normal that the Lean proofs doesn't quite follow the NL proof.
balaclava9
5 days ago
My understanding is that the statements in the Lean proof might not actually correspond to the Navier-Stokes problem. And that requires mathematical insight to be able to verify, which could take quite a while.
omnicognate
6 days ago
If I understand the abstract correctly (big caveat), they aren't saying they didn't prove it. They're saying they gave two proofs, one in natural language and one in Lean, that are not equivalent to each other. I assume the main significance is that the Lean proof is not a formal verification of the natural language one and the natural language proof is not a readable explanation of the Lean one. Both of those things can be desirable, so to complete the set we'd get 4 proofs.
kzrdude
6 days ago
From computer science perspective the conclusion is obvious: untenable to have two representations without an exact translation or machine checked correspondence between then. All we have is a vibe translation using the LLM. The methodology should obviously be improved.
dgacmu
6 days ago
and clearly the computer science perspective is: get rid of the humans and express everything directly in lean so the computers can keep getting work done!
;)
TeMPOraL
6 days ago
But just to clarify: is either of them actually addressing the real Navier-Stokes, or will it turn out we'll end up with two pairs of proofs about something irrelevant to the actual problem?
fasterik
6 days ago
This is the formalization that was proven in Lean. As of now at least, it's believed to be a correct statement of the problem.
https://github.com/google-deepmind/formal-conjectures/blob/8...
balaclava9
5 days ago
Here's from the paper--
"3.1. When the NL paper declares stronger statements than what Lean proves
We commence with an example that complements those in §2. In the following example the AI autoformalisation results in a different Lean proof of a weaker statement."
It seems the Lean version may not be a correct statement of the Navier-Stokes problem.
They go on to say this--
Remark 3.4 (Further potential mistranslations of the Navier-Stokes proof). The above examples require careful manual checking of both the NL proof as well as the Lean proof, which is delicate and highly time consuming. Moreover, the fact that we display only two examples does not mean that these are the only cases of mistranslations.
fasterik
4 days ago
Those are statements about auto-formalization and the NL proof. They're saying that further work needs to be done on verifying whether the Lean and NL proofs are equivalent, which is completely valid. But they're not disputing that the Lean formalization is a correct statement of the Millennium Prize problem. You can see in the link I provided (and the original pull request) that it was written by humans, reviewed by human experts, and is completely independent of the OpenAI effort.
kragen
6 days ago
Nobody is claiming they've misformalized Navier-Stokes.
balaclava9
5 days ago
Yes it could be that neither the NL proof nor the Lean proof correspond to the actual Navier Stokes problem. Here's a quote from the paper--
"Remark 3.4 (Further potential mistranslations of the Navier-Stokes proof). The above examples require careful manual checking of both the NL proof as well as the Lean proof, which is delicate and highly time consuming. Moreover, the fact that we display only two examples does not mean that these are the only cases of mistranslations."
kragen
5 days ago
Yes, but that's irrelevant to what I said, which is that nobody is claiming they've misformalized Navier-Stokes itself.
balaclava9
4 days ago
They are claiming that we do not know if Astra formalized all the elements of the Navier-Stokes proof in Lean correctly.
The Clay Mathematics Institute has not yet accepted the proof.
kragen
2 days ago
The proof is about one of a multitude of possible theorems you could prove about the Navier-Stokes equation. Nobody is claiming that the Navier-Stokes equation itself is misformalized. Rather, they are claiming that what the theorem they proved says about Navier-Stokes is misformalized, in the sense that it's a different theorem than the one informally proven in the natural-language proof.
But nobody is claiming that it's a theorem about a misformalization of the Navier-Stokes equation rather than about the Navier-Stokes equation itself, and nobody is claiming that the theorem they proved in L∃∀N isn't proven. Except random ignorant commenters on Hacker News.
I don't know why this is so difficult. It seems like a lot of commenters here have the reasoning ability of GPT-3, possibly because they're extremely drunk or sleep-deprived, or are actually GPT-3.
plepbpl
3 days ago
> They are claiming that we do not know if Astra formalized all the elements of the Navier-Stokes proof in Lean correctly.
This has nothing to do with whether the lean proof certifies (the real) NS.
dwattttt
6 days ago
They are claiming that the NL proof and the Lean proof are not consistent though: the NL proof is not being validated by the Lean proof, and the Lean proof is not being "explained" by the NL proof.
user
6 days ago
lovasoa
6 days ago
If I understand well, they mean that the thing they proved in lean is not Navier Stokes. And they don't make any statement about whether the natural language proof is correct or not.
kragen
6 days ago
Navier-Stokes is an equation, not a theorem, so there is no such thing as "a proof of Navier-Stokes". The equation is a partial-differential-equation model of viscous fluid flow. Its correctness has never been in doubt: we know it cannot possibly be an exact description of real fluid flow, that it's a pretty good approximate description, and that there exist well-behaved solutions for a number of initial conditions.
What OpenAI purports to have proven, as I understand it, is that certain initial conditions to that equation, plus "forcing" over time (which could be a literal force acting on the fluid such as stirring it with a spoon or some other extrinsic effect) only have finite (and therefore physically plausible) solutions for a finite period of time, after which singularities appear, with the velocity or pressure of some of the fluid approaching infinity as you approach the finite time limit.
This is a result that Terry Tao conjectured in 02014, but without the forcing: http://arxiv.org/abs/1402.0290
I think we can be pretty confident that the L∃∀N proof is really about Navier-Stokes. The question is whether what it says about Navier-Stokes is what we think it says.
nicf
6 days ago
I read them as making a much weaker claim than this: not that the Lean proof isn't valid, just that it is not actually a formalization of the natural-language proof in the PDF they provided alongside it. I haven't heard any PDE people claim that the Lean proof is invalid, and I have heard things from a lot of them that imply that they think it is valid. (I'm a former research mathematician, but this is very far from my specialty, so I'm not really equipped to evaluate this claim myself.)
fasterik
6 days ago
The claim is about the equivalence between two proofs and says nothing about the correctness of either proof. This seems to be confusing a lot of people.
balaclava9
4 days ago
The paper does point out that we don't know if Astra stated the problem correctly in Lean.
There are a number of posts here that consider the correctness of the Lean code with high confidence. This paper I think weakens that confidence.
Generally I think we can agree we don't know if the NL proof is correct, or if the initial statement in Lean is correct. I suppose that's obvious.
fasterik
4 days ago
>or if the initial statement in Lean is correct. I suppose that's obvious.
Is it obvious? The formal statement that Astra proved was written by a human, submitted to a DeepMind repository, and reviewed by human experts in a pull request. It's completely independent of OpenAI's effort. No expert in PDEs or formal verification has disputed it as far as I'm aware.
https://github.com/google-deepmind/formal-conjectures/blob/8...
ActorNightly
6 days ago
Nobody has proven or disproven NS equations.
NS is continuous approximation to what is otherwise a discrete system. Particle collisions are discrete time events that are averaged over time. NS loses accuracy for very, very, very very low fluid densities and energies.
AI "proving" that this approximation can numerically "blow" up does not mean the approximation loses validity.
pohl
6 days ago
> has not formalized the original "natural language" idea of Navier-Stokes incorrectly
Did you mean “not…correctly”?
OhNoNotAgain_99
6 days ago
I'm dutch and not understanding his NL thesis, though i think these days its just as easy to let an ai provide a claim that is actually false, it be easier to hack lean then solve some of those solution for an AI