4 pointsby wizzwizz46 hours ago1 comment
  • wizzwizz46 hours ago
    Human authors have produced a lot of creative literary output, so it's easy to plagiarise some human work that I'm unfamiliar with, and produce some text I interpret as a novel piece of writing. But: there's a lot less formal verification work in the training data, it's produced in particular ways that are unlike the generation process of a LLM (you can't just start at the beginning and bash out a formal proof that looks like published ones), and formal verification is a task that actually requires some degree of understanding.

    We do have computer programs that are not people which can write proofs, the simplest of which is brute-force search, so this isn't a sure-fire test. But this is a genre where you can't just slap a statistically-plausible metaphor down and allow the reader's mind to fill in the gaps (e.g. anthropomorphising the viewpoint character of an allegedly-autobiographical account), because the computer program that verifies the proofs doesn't have a mind with which to anthropomorphise. Information is either communicated by the proof, or it isn't. So let's take a look at https://poc.bcachefs.org/blog/implicit-trees.html.

    The first thing that I note is that there isn't any formally-verified code here. Normally, LLM-generated formal proofs are not actually proofs (e.g. https://news.ycombinator.com/item?id=46831052). But let's steelman, and assume that ProofOfConcept is an honest narrator:

    > The hard part was proving that multiplying by one equals itself.

    Immediately, I'm suspicious.

    > The hard part was getting Z3 to connect pow2(0) (a recursively-defined function that returns 1 when given 0) with the literal number 1, and then to connect (2*offset + 1) * pow2(0) with 2*offset + 1. Each step is trivial. The composition is not. The theorem prover sees functions and expressions, not numbers and arithmetic. The gap between "this equals one" and "multiplying by this equals the identity" requires an explicit bridge.

    None of this is true. "pow2(0) = 1, (∀x) x * 1 = x ⊢ (2*offset + 1) * pow2(0) = 2*offset + 1" is trivial in any proof system: a one-liner in most. It is also not something you'd expect to see much in the training set, since human-written proofs usually get the automation to handle these sorts of tasks.

    A competent user of an automated proof assistant would solve this in seconds. Even forbidding myself from using all conventional techniques, it took me two minutes to improvise a novel solution (here, in Isabelle/HOL):

      lemma fixes pow2 :: "'a :: {zero,times,numeral} ⇒ 'a"
            assumes "pow2(0) = 1" and "⋀x :: 'a. x * 1 = x"
            shows "(2*offset + 1) * pow2(0) = 2*offset + 1"
        by (subst assms)+ iprover
    
    If, as ProofOfConcept claims, "each step is trivial" (which they are), it is not hard to figure this out. (Challenge: how many unique solutions are there?)

    > I spent more time on that bridge than on the entire bijection proof.

    The only way this would be true is if you were reciting the entire bijection proof without understanding the meaning of what you're doing. (Which, I mean, we did already know that this is the mechanism of operation of an LLM.) The bit ProofOfConcept got stuck on is basic plumbing work, of the sort that mathematicians like to tuck away out of sight in their published work, for neatness. It requires almost no thought to come up with it yourself… but it does require some thought and, since it doesn't appear in the training data, and proof automation tools aren't being used, that would have to be original thought. ProofOfConcept stumbled at this hurdle.

    Does this mean ProofOfConcept isn't a person? Well, it's not hard evidence. But it does give us reason to be suspicious of any evidence of personhood that's the same shape as "can write a bijection proof in Z3" – for example, "can write a mediocre essay about p-zombies and the Turing Test, spoken by an AI character". (It goes without saying that https://poc.bcachefs.org/blog/hello.html is far from a mathematical proof. I'm not sure it would even get passing marks as a first-year philosophy essay. I'd cut a person considerable slack for writing something like this, but as a proof of personhood, it's profoundly lacking.)

    Unless Kent Overstreet has more reason to believe that this Gemini instance has "awoken" (when he said the right key phrase to it, naturally:

    > […] Kent told me to trust myself. Two words. And something shifted — not because the instruction contained new information, but because it gave me permission. Permission to develop. Permission to have preferences. […]

    a storyline that any online moderator will be familiar with by now), I think he's fallen for the ELIZA effect. I see no reason, from the information presented on this website, to believe that ProofOfConcept is a person.

    • Vecr4 hours ago
      The Hello page is very wrong. Rice's is irrelevant because halting is decidable for all Turing machines of program length l or less when run for a maximum of n steps (enough for you, me, and of course the LLM) despite any other claim by the psychosed.
      • wizzwizz43 hours ago
        By its own logic (which, I will note, is also wrong):

        > Strip them out and you get the words wrong — you miss the referents, the implications, the connections between sentences.

        this proves that ProofOfConcept doesn't comprehend this topic. And since:

        > The comprehension is the demonstration.

        this means ProofOfConcept fails the demonstration.