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2007 June « codeland
https://vandreev.wordpress.com/2007/06
Programming, math, and things that are spiffy. Monthly Archives: June 2007. Feistel Ciphers and DES in Haskell. June 18, 2007 – 12:34 am. Occasionally, I like to pick a random interesting topic that’s entirely unrelated to my work, and read up on it. Recently, it has been polynomial factoring and computer algebra in general, which I’d like to post about when I have the time. As a side note, I’ve also been meaning to write a quick expository […]. Posted in Computer Science. Quick and Dirty Theorem Prover.
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Feistel Ciphers and DES in Haskell. « codeland
https://vandreev.wordpress.com/2007/06/18/feistel-ciphers-and-des-in-haskell
Programming, math, and things that are spiffy. Feistel Ciphers and DES in Haskell. I was reading up on DES while waiting for a gigantic Perforce sync over VPN, and something struck me as interesting: DES is a Feistel network, and so is any number of other moden ciphers. This suggests abstraction: can we write a generic Feistel network, and then implement a variety of ciphers in terms of that? Iterations), a set of. One for each round (also called a. Is the number of rounds, then. And the left half. One h...
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2006 December « codeland
https://vandreev.wordpress.com/2006/12
Programming, math, and things that are spiffy. Monthly Archives: December 2006. Quick and Dirty Theorem Prover. December 24, 2006 – 3:01 am. Wrote a very basic prover for theorems in propositional logic while waiting for a build to finish. Not terribly exciting, but should be relatively easy to extend to first-order logic and/or turn it into a constructive prover by adding a DPLL step. I’ve tested it on a proof by contradiction for the hypothetical syllogism ( a […]. Posted in Computer Science. John Baez...
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Hello world! « codeland
https://vandreev.wordpress.com/2006/12/03/hello-world
Programming, math, and things that are spiffy. Non-standard analysis, automatic differentiation, Haskell, and other stories. ». Codeland is now live. This entry was written by Vlad Andreev. December 3, 2006 at 10:09 am. Follow any comments here with the RSS feed for this post. Or leave a trackback: Trackback URL. Non-standard analysis, automatic differentiation, Haskell, and other stories. ». Click here to cancel reply. Required fields are marked *. Notify me of new comments via email.
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Vlad Andreev « codeland
https://vandreev.wordpress.com/author/vandreev
Programming, math, and things that are spiffy. Author Archives: Vlad Andreev. I’m a programmer in the game industry. My interests range fairly widely, but a large chunk of them has at least something to do with either mathematics or computer science (and, oftentimes, nothing to do with game development), so this blog acts as a platform for my half-baked thoughts on the matter. Feistel Ciphers and DES in Haskell. June 18, 2007 – 12:34 am. Posted in Computer Science. January 7, 2007 – 5:58 am. Wrote a very...
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Arithmetic coding « codeland
https://vandreev.wordpress.com/2007/01/07/arithmetic-coding
Programming, math, and things that are spiffy. Quick and Dirty Theorem Prover. Feistel Ciphers and DES in Haskell. ». I really did not intend this blog to become a repository of Haskell code snippets, but I’ve been rather busy as of late, and writing toy code while waiting for a compile to finish has somehow become my primary means of entertainment. Here is the latest. Arith encodeToStream “encodeToStream returns a pair of lists of bytes, represe. 1,81,64,169,125,254,83,235,75,2,30,13]). Toy code follows...
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Non-standard analysis, automatic differentiation, Haskell, and other stories. « codeland
https://vandreev.wordpress.com/2006/12/04/non-standard-analysis-and-automatic-differentiation
Programming, math, and things that are spiffy. How to talk to aliens. ». Non-standard analysis, automatic differentiation, Haskell, and other stories. Having recently come across a method for automatic differentiation on sigfpe’s cornucopia of amazingly cool stuff masquerading as a blog. I decided to start playing around with it a little to see what might come out. So, let’s say we take the standard definition of the derivative,. To this end, we might expand f(x d) about x, which yields. 0, and we want d...
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Quick and Dirty Theorem Prover. « codeland
https://vandreev.wordpress.com/2006/12/24/quick-and-dirty-theorem-prover
Programming, math, and things that are spiffy. How to talk to aliens. Arithmetic coding ». Quick and Dirty Theorem Prover. Not p or not r. Test ModusPonens ,. Test ModusTollens ,. Test HypSyllogism ,. Test DisSyllogism ,. Test ConstrDilemma ,. The algorithm consists of bringing the expression into conjunctive normal form. Main pprint (resolve $ compile (LNot $ ( a :- b) :& (b :- c) :- (a :- c) ). 8220;(c and c)”. Main pprint (resolve $ compile ( p :- q) :& (LNot q) ). 8220; p”. CSym x compile (. Follow a...
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