The biggest shame of my life is that I had one of these and somehow managed to lose it.
The error was saying that "infinitely many alphabets can be generated" but there is a finite number of parameters which have a finite range of values. If Knuth had just written "a humongous number of alphabets" he would be correct.
It's not a reward check, but Knuth read one of my articles and emailed me about it [0], which I found pretty cool.<p>[0]: <a href="https://tug.org/TUGboat/tb43-3/tb135chernoff-lwc.pdf" rel="nofollow">https://tug.org/TUGboat/tb43-3/tb135chernoff-lwc.pdf</a>
When I was making my presentation at TUG 2019 he suggested _dart_ as a term for a shape of "two straight edges, one concave arc" which then freed up _arrowhead_ for "two convex, one concave arc".
I wondered how you received a real check since Knuth has not been sending out real checks (as you have noted) for some time now, only to see that you explained it in the very first sentence and I had read over it, just like many people read over the error that you found in the first sentence of the book. Nice one! I wonder what the "Infinitely" was replaced with - probably not "Finitely" :)<p>I had received a check recently and wrote about it too <a href="https://news.ycombinator.com/item?id=49286258">https://news.ycombinator.com/item?id=49286258</a>
It was a bit more than 25 years ago for me, check #790 for $2.88 DT 33, (143).<p>Really need to find another error or point of improvement so as to get the digital account --- I've been reading through TAoCP Vol. 4 Fascicle 7 on _Constraint Satisfaction_, but it's been slow going (though I did find out that it is intentional that he not list beginning of chapter quotes in the index).
What a brilliant teaching technique, think of how many people studied his work for bounties that they would never cash.
I'm surprised we haven't heard of anyone running an AI on Donald Knuth's books to generate the largest collection of checks in existence...
They definitely have; lots of the recent bug reports [0] explicitly acknowledge AI assistance. You can also look at the list of pending bug reports [1] and see how many are from 2026 compared to other years (and it takes many months to get the bug reports enough to add them to this list, so this significantly undercounts things).<p>[0]: <a href="https://tug.org/pipermail/tex-k/" rel="nofollow">https://tug.org/pipermail/tex-k/</a><p>[1]: <a href="https://tug.org/texmfbug/newbug.html" rel="nofollow">https://tug.org/texmfbug/newbug.html</a>
He is quite methodical and meticulous --- I doubt that there is much in the training data which isn't already accounted for in his research for his writings.<p>I only managed to get one check (for an error and a point of improvement) for _very_ minor points in _Digital Typography_ which was facilitated by my having been fascinated by typography since reading Oscar Ogg's _The 26 Letters_ and his cousin Warren Chappell's _The Living Alphabet_ when I was 8 or so.
The next headline will read: "AI pilled vibecoders bankrupt a once prominent computer scientist, the figure will surprise you!"
I wonder if someone has used an LLM yet to analyze Knuth’s books and find errors to inundate him with? Please don’t do that (although I’m sure it’s possible).
Awesome! I know the feeling, I have two myself.
<a href="https://x.com/loginn/status/1367475093719416833" rel="nofollow">https://x.com/loginn/status/1367475093719416833</a><p>(Hmm maybe I should also write a blogpost about this)
I also got one for catching DEK out for claiming "Alan Turing broke the Enigma".<p>That claim goes to the Polish cryptoanalyst Marian Rejewski instead, of course (<a href="https://en.wikipedia.org/wiki/Marian_Rejewski" rel="nofollow">https://en.wikipedia.org/wiki/Marian_Rejewski</a>); what Alan Turing and Tommy Flowers did was automate the breaking, which was important because it had to be done again every day (due to the many combinations of configurations of the Enigma).
I bet the mailing cost was more than 0x$2.00 for Knuth.
Sadly I think this is the end of an era. Someone should probably run an AI fact checker on this and send him the rest of any errors. Or he could change the nature or requirement of the reward, if somehow it can be proved the error could not have been found without a human's effort.
Interesting how no other writers in the field seem to have adopted Knuths' strategy to get their books proofread to the point of being bullet proof.
No other writers have the stature of Knuth. The motivation to proof-read here is not the monetary reward after all.
Bjarne Stroustrup did, at some point at least. I have a $32 real check from him for finding an error in "The C++ Programming Language (Special Edition)".
Few other authors works have the legs to be reprinted sufficiently.
I know a guy (ricbit) who have 4 or more
But what's the most Reward checks anyone has ever held?
Just FYI for HN - if there is anyone looking to make big money in the coming years there are no fully signed TAOCP first editions anywhere. You would honestly print so much money if you could get all the first edition volumes signed.
He is incredibly generous with his signings --- even doing one on the spur of the moment in his home when one of the presenters mentioned that he'd been unable to source a copy of _Mathematical Fun and Games_ (I had a copy I'd planned on getting signed, but instead passed it to his wife and insisted that she get a photo of DEK signing it for her husband and that they keep it).
Images weren't loading for me, here's a Wayback Machine link <a href="https://web.archive.org/web/20260412143311/https://www.thomas-huehn.com/knuth-reward-check/" rel="nofollow">https://web.archive.org/web/20260412143311/https://www.thoma...</a>
The HN URL is missing the trailing slash; see <a href="https://news.ycombinator.com/item?id=50036221">https://news.ycombinator.com/item?id=50036221</a>
Thank you for this! Images weren't loading for me, either.
We updated the URL to add the slash, thanks!
Can we adjust the URL to have a final trailing slash? The HN URL points to,<p><pre><code> https://www.thomas-huehn.com/knuth-reward-check
</code></pre>
But this means the images, whose hrefs are like,<p><pre><code> src="./bug-report-knuth-2006.jpg"
</code></pre>
Don't load; that relative-ref results in a URL of<p><pre><code> https://www.thomas-huehn.com/bug-report-knuth-2006.jpg
</code></pre>
Which is a 404.<p>One can infer that the post's URI is like a "directory" of the subresources for the post, including those images; the URL of<p><pre><code> https://www.thomas-huehn.com/knuth-reward-check/
</code></pre>
(n.b. the trailing slash) adjusts the resolution of the image's relative-ref now to:<p><pre><code> https://www.thomas-huehn.com/knuth-reward-check/bug-report-knuth-2006.jpg
</code></pre>
And the images load. Yes, trailing slashes in URLs are significant in the case of resolving a relative ref like that.<p>If the author is here, you might consider redirecting the non-slash to the slash.<p>> <i>But why will you find me there with the entry “0x$1.20”, i.e. decimal $2.88?</i><p>I know Knuth has his own notation here, (it is clearly noted at the bottom of the BOSS page) but 0x1.20 should really be decimal 1.125.
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i was expecting an article about farming these with claude.<p>thank god it wasn't that lol
True AGI will arrive when an LLM will be able to provide ALL remaining mistakes in Donald Knuth's books. And kill one more amazing thing in the process.