5 ms·

How a Startup from Krakow Got Mentioned in “The Art of Computer Programming”

309 points by mci 9y ago

DoreenMichele 9y ago
Very fun. I didn't know what a Hamiltonian graph was: https://en.m.wikipedia.org/wiki/Hamiltonian_path https://en.m.wikipedia.org/wiki/Hamiltonian_path
TeMPOraL 9y ago
Nice one, congrats! (Also imagine my surprise, seeing my home town mentioned on the front page of HN this early morning! I thought for a second that sleep deprivation finally got the best of me.) I wish you best of luck. I used to be in the Kraków's 3DP commumity back in Materialination heydays. That was before you were founded, but maybe we've crossed paths there.
svat 9y ago
Apart from the 2016 Christmas Tree lecture [1] (which is even available in 3D [2]), Knuth also mentioned this “mysterious package from Poland” during an earlier (a week earlier) lecture at Brown University [3] (about 25 minutes in). I love this talk (he gave roughly the same talk at both places, though one was more rushed than the other). He goes pretty deep into history — for example his discussion of Hamiltonian tours (knight's tours etc.) in Sanskrit poetry is at a level of detail that I have not seen in any other published source in English. After knowing that he was interested in this topic, I requested a contemporary Sanskrit poet to write a “knight's tour” Sanskrit poem, and gave it to Knuth as a gift. He loved it! [1]: https://www.youtube.com/watch?v=DjZB9HvddQk https://www.youtube.com/watch?v=DjZB9HvddQk [2]: https://www.youtube.com/watch?v=9DrzK3Z0rg0 https://www.youtube.com/watch?v=9DrzK3Z0rg0 [3]: https://www.youtube.com/watch?v=4UFkH5ZlVqQ https://www.youtube.com/watch?v=4UFkH5ZlVqQ
- tuomosipola 9y ago
  What a cool gift. I didn't know Knuth was into Sanskrit poetry. Nice to notice that people from STEM fields are interested in things like that. I'm always happy to see something related to ancient languages in HN.
  - kbart 9y ago
    Actually, based on my limited social circle, people from STEM get into Sanskrit much faster, because of its complex rules and similarity to programming (it's their words, I don't know Sanskrit, so can't confirm it). Learning Sanskrit is kinda "cool" now. Also, my girlfriend (not from STEM background) knows Sanskrit pretty well and keeps telling me that she feels like writing code (as she imagines that from seeing me doing or talking about it) when translating text to/from Sanskrit.
  - chubot 9y ago
    There is perhaps a technical reason for this. Computer languages are described using BNF notation, apparently invented in the 20th century, but others have noted that Panini did this 2500 years earlier, describing Sanskrit with a similar notation: https://en.wikipedia.org/wiki/Backus%E2%80%93Naur_form https://en.wikipedia.org/wiki/Backus%E2%80%93Naur_form The idea of describing the structure of language using rewriting rules can be traced back to at least the work of Pāṇini (ancient Indian Sanskrit grammarian and a revered scholar in Hinduism who lived sometime between the 7th and 4th century BCE).[1][2] His notation to describe Sanskrit word structure notation is equivalent in power to that of Backus and has many similar properties. Citation: https://dl.acm.org/citation.cfm?id=363165 https://dl.acm.org/citation.cfm?id=363165 I can't copy the text here, but it's worth a read: https://www.deepdyve.com/lp/association-for-computing-machinery/p-nini-backus-form-suggested-993dM00q6Q https://www.deepdyve.com/lp/association-for-computing-machin... Knuth is mentioned in the same letter as Panini, regarding the naming of "BNF". https://www.infinityfoundation.com/mandala/t_es/t_es_rao-t_syntax.htm https://www.infinityfoundation.com/mandala/t_es/t_es_rao-t_s... Knuth invented LR parsing of context free grammars: https://en.wikipedia.org/wiki/LR_parser https://en.wikipedia.org/wiki/LR_parser LR parsers were invented by Donald Knuth in 1965 as an efficient generalization of precedence parsers. Knuth proved that LR parsers were the most general-purpose parsers possible that would still be efficient in the worst cases.
    - bakul 9y ago
      It is widely assumed Pāṇinian languages (generated using the formalism he used for describing Sanskrit) are context free languages but the following paper argues that they are a much larger set than CFLs. https://web.stanford.edu/~kiparsky/Papers/panini-1.pdf https://web.stanford.edu/~kiparsky/Papers/panini-1.pdf My Knuth tale: I happened to be sitting near Prof. Knuth at a dinner last December and I mentioned to him Pāṇini & Sanskrit in the context of something I work on now and then. He heard Sanskrit and immediately pointed me to this Christmas lecture of his!
limaoscarjuliet 9y ago
As someone who brought a branch of a US company to Krakow (my birth place), I can only say - great job and congrats!
unusximmortalis 9y ago
:) beautiful story, thanks for sharing
metaphor 9y ago
FYI Prof. Knuth presents the problem at 16:50 into the lecture[1] linked in the blog, then shows off his Sinterit trinket at 18:30ish. [1] https://youtu.be/DjZB9HvddQk?t=1010 https://youtu.be/DjZB9HvddQk?t=1010
pavbelshippable 9y ago
Nice hack I would say
rkachowski 9y ago
What does it say in Knuth's response? "Of course you could have used the ( <word here> font/foot???)"
- mci 9y ago
  cmtt aka Computer Modern Typewriter, the same font as in the diagram from TAOCP.
dbdr 9y ago
Retrospectively considering "It would be nice to own a 3D-printed object like this!" as an understatement (i.e. a "mistake" in his book) was a clever hack to create an excuse for giving them one of his famous reward checks. And kind and hilarious to boot! Prof. Knuth is amazing.
hnkain 9y ago
It looks like they got the N upside-down. The top of the N (the end with two serifs, as you can see here http://www.identifont.com/similar?TI http://www.identifont.com/similar?TI ) is pointing to M, rather than the bottom.
- jammaloo 9y ago
  It looks like you are correct. They seem to have taken the design from Donald Knuth, who put the N in upside down.
jakozaur 9y ago
Startup opportunity: Custom 3D printed dice. Pick any variation (e.g. less boring than cube). Different text and order. Excellent swag.
- Shoothe 9y ago
  I was looking for a 4D dice with 8 sides, just dots from 1 to 4 and couldn't find it (the same one as used in Sorcery's Swindlestones) so I'd definitely be interested.
  - DanBC 9y ago
    Not dots, but there are these: https://twitter.com/Meroka_BM/status/840420992048586752 https://twitter.com/Meroka_BM/status/840420992048586752 And blank dice are easy enough to get: https://www.amazon.com/Blank-Sided-Educational-Counting-Organza/dp/B01MZZET0F https://www.amazon.com/Blank-Sided-Educational-Counting-Orga...
    - Shoothe 9y ago
      I've got the double 4d dice (white) but it didn't occur to me that blank dice and a little bit of paint can just do the job. Thanks!
- tannhaeuser 9y ago
  You're limited to the other Platonic solids [1] for dice having more than the standard 6 faces if you want the odds to be the same, aren't you though? [1]: https://en.wikipedia.org/wiki/Platonic_solid https://en.wikipedia.org/wiki/Platonic_solid
  - coke12 9y ago
    Since you can assign the same label to multiple faces, it seems like you could construct a fair die that's not a Platonic solid. I wonder if the rule is that the total face area for each label must be the same?
YeGoblynQueenne 9y ago
Of course this is exceedingly cool and the item itself is of good quality, but it should be said that it's possible to make your own twenty-sided dice with whatever you want on their faces, by ordering blank dice on the internet and painting your desired symbols by hand. There's also companies that can print you the diece you want. In fact, gaming lore says that in the early days of pen-and-paper RPGs, gamers couldn't find anyone selling the polyhedral dice they needed, so they ordered instead Platonic solids used for demonstration of geometric objects' properties from school supplies retailers and filled in the numbers by hand, as above. Which in no way means that any early d20s were missing a few 1's and 2's :|

309 points by mci 9y ago

Very fun. I didn't know what a Hamiltonian graph was: https://en.m.wikipedia.org/wiki/Hamiltonian_path https://en.m.wikipedia.org/wiki/Hamiltonian_path

TeMPOraL 9y ago

Nice one, congrats! (Also imagine my surprise, seeing my home town mentioned on the front page of HN this early morning! I thought for a second that sleep deprivation finally got the best of me.) I wish you best of luck. I used to be in the Kraków's 3DP commumity back in Materialination heydays. That was before you were founded, but maybe we've crossed paths there.

svat 9y ago

Apart from the 2016 Christmas Tree lecture [1] (which is even available in 3D [2]), Knuth also mentioned this “mysterious package from Poland” during an earlier (a week earlier) lecture at Brown University [3] (about 25 minutes in). I love this talk (he gave roughly the same talk at both places, though one was more rushed than the other). He goes pretty deep into history — for example his discussion of Hamiltonian tours (knight's tours etc.) in Sanskrit poetry is at a level of detail that I have not seen in any other published source in English. After knowing that he was interested in this topic, I requested a contemporary Sanskrit poet to write a “knight's tour” Sanskrit poem, and gave it to Knuth as a gift. He loved it! [1]: https://www.youtube.com/watch?v=DjZB9HvddQk https://www.youtube.com/watch?v=DjZB9HvddQk [2]: https://www.youtube.com/watch?v=9DrzK3Z0rg0 https://www.youtube.com/watch?v=9DrzK3Z0rg0 [3]: https://www.youtube.com/watch?v=4UFkH5ZlVqQ https://www.youtube.com/watch?v=4UFkH5ZlVqQ

tuomosipola 9y ago
What a cool gift. I didn't know Knuth was into Sanskrit poetry. Nice to notice that people from STEM fields are interested in things like that. I'm always happy to see something related to ancient languages in HN.
- kbart 9y ago
  Actually, based on my limited social circle, people from STEM get into Sanskrit much faster, because of its complex rules and similarity to programming (it's their words, I don't know Sanskrit, so can't confirm it). Learning Sanskrit is kinda "cool" now. Also, my girlfriend (not from STEM background) knows Sanskrit pretty well and keeps telling me that she feels like writing code (as she imagines that from seeing me doing or talking about it) when translating text to/from Sanskrit.
- chubot 9y ago
  There is perhaps a technical reason for this. Computer languages are described using BNF notation, apparently invented in the 20th century, but others have noted that Panini did this 2500 years earlier, describing Sanskrit with a similar notation: https://en.wikipedia.org/wiki/Backus%E2%80%93Naur_form https://en.wikipedia.org/wiki/Backus%E2%80%93Naur_form The idea of describing the structure of language using rewriting rules can be traced back to at least the work of Pāṇini (ancient Indian Sanskrit grammarian and a revered scholar in Hinduism who lived sometime between the 7th and 4th century BCE).[1][2] His notation to describe Sanskrit word structure notation is equivalent in power to that of Backus and has many similar properties. Citation: https://dl.acm.org/citation.cfm?id=363165 https://dl.acm.org/citation.cfm?id=363165 I can't copy the text here, but it's worth a read: https://www.deepdyve.com/lp/association-for-computing-machinery/p-nini-backus-form-suggested-993dM00q6Q https://www.deepdyve.com/lp/association-for-computing-machin... Knuth is mentioned in the same letter as Panini, regarding the naming of "BNF". https://www.infinityfoundation.com/mandala/t_es/t_es_rao-t_syntax.htm https://www.infinityfoundation.com/mandala/t_es/t_es_rao-t_s... Knuth invented LR parsing of context free grammars: https://en.wikipedia.org/wiki/LR_parser https://en.wikipedia.org/wiki/LR_parser LR parsers were invented by Donald Knuth in 1965 as an efficient generalization of precedence parsers. Knuth proved that LR parsers were the most general-purpose parsers possible that would still be efficient in the worst cases.
  - bakul 9y ago
    It is widely assumed Pāṇinian languages (generated using the formalism he used for describing Sanskrit) are context free languages but the following paper argues that they are a much larger set than CFLs. https://web.stanford.edu/~kiparsky/Papers/panini-1.pdf https://web.stanford.edu/~kiparsky/Papers/panini-1.pdf My Knuth tale: I happened to be sitting near Prof. Knuth at a dinner last December and I mentioned to him Pāṇini & Sanskrit in the context of something I work on now and then. He heard Sanskrit and immediately pointed me to this Christmas lecture of his!

limaoscarjuliet 9y ago

As someone who brought a branch of a US company to Krakow (my birth place), I can only say - great job and congrats!

unusximmortalis 9y ago

:) beautiful story, thanks for sharing

metaphor 9y ago

FYI Prof. Knuth presents the problem at 16:50 into the lecture[1] linked in the blog, then shows off his Sinterit trinket at 18:30ish. [1] https://youtu.be/DjZB9HvddQk?t=1010 https://youtu.be/DjZB9HvddQk?t=1010

pavbelshippable 9y ago

Nice hack I would say

rkachowski 9y ago

What does it say in Knuth's response? "Of course you could have used the ( <word here> font/foot???)"

mci 9y ago
cmtt aka Computer Modern Typewriter, the same font as in the diagram from TAOCP.

dbdr 9y ago

Retrospectively considering "It would be nice to own a 3D-printed object like this!" as an understatement (i.e. a "mistake" in his book) was a clever hack to create an excuse for giving them one of his famous reward checks. And kind and hilarious to boot! Prof. Knuth is amazing.

hnkain 9y ago

It looks like they got the N upside-down. The top of the N (the end with two serifs, as you can see here http://www.identifont.com/similar?TI http://www.identifont.com/similar?TI ) is pointing to M, rather than the bottom.

jammaloo 9y ago
It looks like you are correct. They seem to have taken the design from Donald Knuth, who put the N in upside down.

jakozaur 9y ago

Startup opportunity: Custom 3D printed dice. Pick any variation (e.g. less boring than cube). Different text and order. Excellent swag.

Shoothe 9y ago
I was looking for a 4D dice with 8 sides, just dots from 1 to 4 and couldn't find it (the same one as used in Sorcery's Swindlestones) so I'd definitely be interested.
- DanBC 9y ago
  Not dots, but there are these: https://twitter.com/Meroka_BM/status/840420992048586752 https://twitter.com/Meroka_BM/status/840420992048586752 And blank dice are easy enough to get: https://www.amazon.com/Blank-Sided-Educational-Counting-Organza/dp/B01MZZET0F https://www.amazon.com/Blank-Sided-Educational-Counting-Orga...
  - Shoothe 9y ago
    I've got the double 4d dice (white) but it didn't occur to me that blank dice and a little bit of paint can just do the job. Thanks!
tannhaeuser 9y ago
You're limited to the other Platonic solids [1] for dice having more than the standard 6 faces if you want the odds to be the same, aren't you though? [1]: https://en.wikipedia.org/wiki/Platonic_solid https://en.wikipedia.org/wiki/Platonic_solid
- coke12 9y ago
  Since you can assign the same label to multiple faces, it seems like you could construct a fair die that's not a Platonic solid. I wonder if the rule is that the total face area for each label must be the same?

YeGoblynQueenne 9y ago

Of course this is exceedingly cool and the item itself is of good quality, but it should be said that it's possible to make your own twenty-sided dice with whatever you want on their faces, by ordering blank dice on the internet and painting your desired symbols by hand. There's also companies that can print you the diece you want. In fact, gaming lore says that in the early days of pen-and-paper RPGs, gamers couldn't find anyone selling the polyhedral dice they needed, so they ordered instead Platonic solids used for demonstration of geometric objects' properties from school supplies retailers and filled in the numbers by hand, as above. Which in no way means that any early d20s were missing a few 1's and 2's :|