I found a bug in Algorithm D, the long division algorithm in Knuth's "The Art of Computer Programming". It was discussed on HN a couple of times https://news.ycombinator.com/item?id=26562819 as well as on other websites. I sent a letter to Knuth and received a check and an annotated reply. The updated Theorem B, which was unchanged since 1969 is now dated 2026.

While searching for vulnerable implementations I also found a "bug" in llvm, so I expanded a bit on that too.

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jason_s a day ago | parent | next [-]

Congratulations! Wow, you got a legendary $2.56 check....

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WillAdams 3 hours ago | parent | next [-]

Unfortunately, one no longer gets physical checks, instead, one gets an account in The Bank of the Island of San Seriffe:

https://www-cs-faculty.stanford.edu/~knuth/boss.html

(unfortunately, I have yet to find another typo since getting my $2.88 for _Digital Typography_)

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bluGill 19 minutes ago | parent | next [-]

Close enough. If I ever got such a check it would be professionally framed and hung on my wall. As would most people reading this.

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malisper 2 hours ago | parent | prev [-]

You still get a physical piece of paper that looks like a check; it's just not a valid check.

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nk_kolja 2 hours ago | parent [-]

It can still be cashed in, though not in any bank, you need to contact Knuth beforehand.

For me it will stay framed on the wall.

	▲	WillAdams an hour ago \| parent [-]
		I wonder if one can do the reverse? Turn in a physical check and get an account?

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warmwaffles 3 hours ago | parent | prev [-]

Hopefully framed it and put it on the wall.

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AndruLuvisi an hour ago | parent | prev [-]

Wow, congratulations on finding this most epic bug!