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vilhelm_s

Re:Navier–Stokes Lost in Translation on Friday October 09, 2026 @03:09PM (#50025282)
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.

Re:Navier–Stokes Lost in Translation on Thursday October 08, 2026 @06:05PM (#50013058)
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.
Re:Navier–Stokes Lost in Translation on Wednesday October 07, 2026 @09:36PM (#50001000)
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.

This decision is a direct consequence of the EU decision, Pricerunner applied the precedent from that case and claimed that Google discriminated against them in the same way. (https://www.delphi.se/eu-competition-blog/private-enforcemen..., https://www.domstol.se/nyheter/2026/07/google-is-to-pay-dama...)
Re:Int a = 5; a = a++ + ++a; a =? (2011) on Thursday May 14, 2026 @06:55PM (#48142347)
The "shall" in the standard means it's undefined behavior. This is explained in the "Conformance" section,

> 2. If a ‘‘shall’’ or ‘‘shall not’’requirement that appears outside of a constraint is violated, the behavior is undefined. Undefined behavior is otherwise indicated in this International Standard by the words ‘‘undefined behavior’’ or by the omission of any explicit definition of behavior. There is no difference in emphasis among these three; they all describe ‘‘behavior that is undefined’’.

Compilers will not refuse to compile the code, indeed the blog post we are all commenting on reports the results from a bunch of different compilers. Historically the reason the C standard specified a lot of undefined behavior is that the actually existing C compilers at the time compiled the code but disagreed about the output.

Re:"Why not just use Lean?" on Monday April 27, 2026 @05:07PM (#47927318)
Yeah. I guess the abstract type approach saves some memory, but it's a constant factor thing, not an asymptotic improvement. The comment that Lean wastes "tens of megabytes" seems telling: it seems like something that would be a critical advantage in the 1980s and 1990s, when Paulson first fought these battles, but maybe less important today...
The order was not that he had to produce the coins, just that he cooperate in tracking them down. Telling them where he had stashed it would have been fine.
We need to do "leap hours" anyway--just today they changed to daylight saving time in the U.S.! And time zones are also adjusted every now and then, which also amounts to a one-hour change in the affected regions. Even if we didn't have continous practice with leap seconds, I think we could definitely include an extra one-hour shift for earth rotation reasons along with all the other ones.
They cite this paper which gives the concept: https://www.sciencedirect.com/science/article/pii/S002234681... . The mechanism of injury in spina bifida is that the spinal cord gets exposed and damaged. Current surgery will close the spinal canal to prevent further exposure, but it doesn't do anything to reverse the damage that has already happened. The stem cells integrate into the neural tissue and hopefully help the axons heal.
There is a copy of a court order here which gives more legal details [https://www.universalhub.com/files/attachments/2026/culleton...]

> The Fifth Circuit has held that the VWP statute “‘unambiguously’ limits an alien’s means of contesting removal solely to an application for asylum.” McCarthy v. Mukasey, 555 F.3d 459, 460 (5th Cir. 2009) (citation omitted). And once an individual violates the terms of the VWP by remaining in the United States for more than ninety days, the individual is no longer entitled to contest removal on any other basis. Id. at 462. This is true even when an individual has a pending adjustment of status application on the basis of their marriage to a U.S. citizen. Id. at 460, 462.

> Culleton concedes he is removable under the VWP. Reply 10. But he argues that because USCIS accepted and began processing his adjustment of status application, he is entitled to due process protections in its fair adjudication. Id. at 9. The Fifth Circuit has foreclosed this very argument, reasoning that the VWP waiver includes a waiver of due process rights. See Mukasey, 555 F.3d at 462. And “[t]he fact that [Culleton] applied for an adjustment of status before the DHS issued its notice of removal is of no consequence.” Id.

Re:Broken Proofs and Broken Provers on Wednesday February 04, 2026 @09:05AM (#46885934)
I don't think it's that subtle: it would be enough to have a continuous integration tool that tries to compile the proofs that are checked into version control and raises an error if it fails.

The linked blog post says "Unfortunately, a student once submitted work containing this error; it was almost entirely incorrect and he had no idea." I guess the student probably was aware that not every proof had gone through, and that the that he saw like "99 out of 100 proofs succeeded" and assumed that meant that he had mostly completed the task, not realizing that a false theorem would be used to the give incorrect proofs for the rest of the file.

But he had not been an apprentice before making this, he started the apprenticeship that year, and this is supposed to be the first thing he ever painted.

> Michelangelo's biographers—Giorgio Vasari (1511–1574) and Ascanio Condivi (1525–1574)—tell us that, aside from some drawings, his first work was a painted copy after a well-known engraving by Martin Schongauer (1448–1491) showing Saint Anthony tormented by demons. Made about 1487–88 under the guidance of his friend and fellow pupil Francesco Granacci, Michelangelo's painting was much admired; it was even said to have incited Ghirlandaio's envy. [https://www.metmuseum.org/exhibitions/listings/2009/michelan...]

The idea is that e.g. the government would give you an app that lives on your phone. When you apply for the app you provide some documents to prove your age, but you don't say anything about what sites you plan to visit. When you want to visit an age-restricted site you use the app to generate a proof that you have it, but the site doesn't learn anything more than that, and the government doesn't learn that you used the app.
Re:Mind-reading devices can now predict preconscious thoughts on Monday November 24, 2025 @03:58PM (#46039236)
Yeah, that sounds very unlikely. The full paper dismisses the possibility:

> Another possible explanation to consider is that the current indings were caused by cross-cueing (one hemisphere informing the other hemisphere with behavioural tricks, such as touching the left hand with the right hand). We deem this explanation implausible for four reasons. First, cross-cueing is thought to only allow the transfer of one bit of information (Baynes et al., 1995). Yet, both patients could localize stimuli throughout the entire visual field irrespective of response mode (Experiments 1 and 5), and localizing a stimulus requires more than one bit of information. Second, [...]

I get the impression that the authors of the paper have some kind of woo (nonmaterialist) view of consciousness. But they also mention this possiblity, which seems more plausible to me:

> Finally, a possibility is that we observed the current results because we tested these patients well after their surgical removal of the corpus callosum (Patient DDC and Patient DDV were operated on at ages 19 and 22 years, and were tested 10–16 and 17–23 years after the operation, respectively). This would raise the interesting possibility that the original split brain phenomenon is transient, and that patients somehow develop mechanisms or even structural connections to re-integrate information across the hemispheres, particularly when operated at early adulthood.

Re:Europe is scaling back its landmark privacy and AI laws on Thursday November 20, 2025 @12:36AM (#45989305)
They are regulating websites anyway, surely they can just invent some standard format to say what function each cookie has. How about requiring that the name of every cookie has to start with one of "Strictly Necessary", "Functional", "Performance", and "Targeting/Advertising"?
The F-22 itself was delayed because of the end of the cold war. The original plans were to have it enter service in 1995, and then this slipped by a year or two. They could have had it being pass produced from 1997, but they delayed it because of the peace dividend. (This is from Aronstein et al, "ATF to F-22 Raptor"). So one should not consider the 2005 date as "how long it took".
Re:Zed is now available on Windows on Thursday October 16, 2025 @09:12AM (#45604918)
The Rust compiler always produces quite large binaries compared to other programming language. I notice there's a (closed) issue on the Zed github [https://github.com/zed-industries/zed/issues/34376],

> At this time, we prioritize performance and out-of-the-box functionality over minimal binary size. As is, this issue isn't very actionable, but if you have concrete optimization ideas that don't compromise these priorities, we'd be happy to consider them in a new issue.

Surely your graph shows it declining dramatically? If you zoom out a bit [https://crimeforecast.substack.com/p/explaining-the-crime-de...] we're currently at almost an all-time low, you have to go back to the 1950s to find similarly low numbers.
I'm guessing they mean it detected a different vehicle and pedestrian but not the ones it hit. (If it was the victim I don't think they would have said "a".)
The radioactive lead isotopes come from decay of uranium and thorium, so lead from different mines will have different isotope ratios depending on how much U and Th happened to be in that ore.

Not all leaded gasoline was the same either:

> 206Pb/207Pb ratios commonly found in Pb ores throughout the world range between 16.0–18.5 and 1.19–1.25, respectively (Hansmann and Köppel, 2000). Exception to this rule is the commonly used Pb ore from the Broken Hill deposit, Australia, which is characterised by extremely low 206Pb/207Pb ratios (1.03–1.10). On the other hand, Pb originating from the Mississippi Valley ore deposit, USA, exhibits significantly more radiogenic Pb isotopic composition (206Pb/204Pb N20.0; 206Pb/207Pb= 1.31–1.35) (Doe and Delevaux, 1972). American leaded gasoline reflected therefore significantly higher 206Pb/207Pb ratios compared to European gasoline (Fig. 1). The introduction of the European leaded gasoline around 1945 resulted in a steep decrease of the 206Pb/207Pb ratio of atmospheric Pb (Weiss et al., 1999; data from peat deposits). The isotopic composition of leaded gasoline was to some extent dependent on economical factors, such as the availability and price of Pb ores and has evolved due to the different Pb ores used. For example, Pb used for French leaded gasoline originated from Australian, Moroccan and Swedish ores and the contribution of the separate ores changed during time (Véron et al., 1999). It is therefore indispensable to gather data concerning the origin of gasoline used in studied regions.

[from https://sci-hub.ru/https://doi.org/10.1016/j.envint.2007.10....]

The telescope is panning to keep the comet still in the frame during the exposure.
Re:New records on Wendelstein 7-X on Monday July 21, 2025 @04:33PM (#44640083)
Batteries are nowhere near that cheap.

Currently the cheapest non-intermittent energy source is gas; solar costs about half as much, and nuclear costs 50% more than gas [0]. Battery storage is currently competitive with gas for storing around 4 hours of electricity [1].

If we would want to replace the baseload with solar + batteries we would need to store 12 hours instead, during the dark half of the day, so it would cost 3x as much, 200% more than gas.

Maybe we can hope for battery prices to drop, but extrapolating from a Wright's law curve, for them to become cheaper by a factor of 3 we need to produce 32 times as many of them [1, again], it won't happen in the near future.

[0] https://www.eia.gov/outlooks/aeo/electricity_generation/pdf/... [1] https://www.lesswrong.com/posts/mnaEgW9JgiochnES2/2024-was-t...

I mean, you definitely can't build your own unsafePerformIO without dropping the state token. I have never thought deeply about it, but if you had asked me I would probably have guessed that using the token linearly would be enough to ensure safety. That's not the same as it being "normal", of course.
Re:The Untold Mystery Upending Egon Schiele's Legacy on Monday April 07, 2025 @11:15AM (#43612477)
Surely the child's father was Anton Peschka? Gertrude was engaged to him, later married him, and his mother raised the child. I don't think the article suggests otherwise.
Re:LINUX is obsolete (1992) on Saturday February 08, 2025 @11:43AM (#42984178)
I think the gap was just beginning to emerge around 1990. Until then, people really were re-developing the full computing stack based on new research every few years. Rob Pike identified 1990 as the year systems research became irrelevant[0] because from then on people kept on using and iterating on the same software.

[0] https://tianyin.github.io/misc/irrelevant.pdf

Re:CMU, Princeton join forces to use AI for Nuclear Fusion on Thursday November 07, 2024 @12:59PM (#42079101)
The radioactivity generated from neutron activation is low-level, so you don't need to worry about accidents releasing lots of radioactivity, or about how to store waste for a long time. There are a lot of people worrying about those two things for fission reactors.

Also, the fuel for fusion reactors is much more plentiful. If we went all in on fission we might run out of easily minable uranium ore in a century or so, so it would be nice to have fusion reactors ready to take over then.

Re:Please just stop saying "just" (2019) on Tuesday November 05, 2024 @08:33AM (#42051336)
It's not about written instructions to an audience who has never set up a website though, it's about an "engineer" and a "senior engineer" on the same team talking to each other.
It's the other way around, there was a class action, but the eventual outcome was that everyone needs to sue individually instead.
No, it was settled a few months ago. https://news.bloomberglaw.com/business-and-practice/lawyers-...

> The plaintiffs had asked for $5 billion in damages, but the settlement provided no monetary relief. Individuals will be allowed to file claims in state courts, and Boies Schiller lawyers have said they already filed more than 1,000 such cases in California state court, with plans to file many more.

No, the point is that the proof itself should be written in the Coq language. The original 4-color proof in 1976 was written in English. They used computer programs to do certain computations, but the proof that those programs were correct and that they were computing the right thing was written in English and checked by humans.

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