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HP Patents Bignum Implementation From 1912 144

I Don't Believe in Imaginary Property writes "The authors of GMP (the GNU Multiple Precision Arithmetic Library) were invited to join Peer-to-Patent to review HP's recent patent on a very old technique for implementing bignums because their software might infringe. Basically, HP's patent claims choosing an exponent based on processor word size. If you choose a 4-bit word size and a binary number, you end up working in hexadecimal. Or for a computer with a 16-bit word and a base-10 number, you use base 10,000 so that each digit of the base-10,000 number would fit into a single 16-bit word. The obvious problem with that is that there's plenty of prior art here. Someone who spent a few minutes Googling found that Knuth describing the idea in TAOCP Vol. 2 and other citations go back to 1912 (which implemented the same algorithm using strips of cardboard and a calculating machine). None of this can be found in the 'references cited' section. Even though the patent examiner did add a couple of references, they appear to have cited some old patents. The patent issued a few months ago was filed back in October of 2004, and collected dust at the USPTO for some 834 days."
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HP Patents Bignum Implementation From 1912

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  • by nebaz ( 453974 ) on Monday January 04, 2010 @11:20PM (#30650654)

    In the example section they give, they are dividing up the "bigdecimal" in decimal, rather than binary components. The number of decimal digits depends on the word size. For example, an 8 bit word has 0-255 as possible storage, but in decimal, you could store 0-99, but not 0-999. So you would store the number 102,345 as 10, 23, and 45 in 3 separate words if you had an 8 bit word. They claim that this is more efficient than binary for rendering back to decimal, though I can't see how this is more efficient than straight binary storage.

  • by _merlin ( 160982 ) on Monday January 04, 2010 @11:21PM (#30650664) Homepage Journal

    If you had comprehension skills, you'd be able to ascertain that it relates to an implementation of an arbitrary precision numerics engine, a la GNU MultiPrecision (aka GMP). The technique has been around for close to a century, if not longer.

  • by martijnd ( 148684 ) on Monday January 04, 2010 @11:30PM (#30650740)

    "A few minutes googling"

    Less than 10 years ago it would have taken multiple trips to (several) libraries by a very persistant person to find this information. (The kind of person who would read an obscure mailing list about patent abuse).

    Most likely a cursory review by a bored patent clerk (as he is working on the next E=MC^2) would have turned up nothing, and the patent would have passed.

    Now any Slashdotter with a minute to spare can find the same information.

    Its interesting to see how we are getting to grips with information overload.

  • by butlerm ( 3112 ) on Tuesday January 05, 2010 @12:05AM (#30651028)

    PostgreSQL starting storing NUMERIC columns in base 10000 six or seven [] years ago. A nice trick, but not exactly rocket science. If you have a high school level education in computer science, you should know how to do stuff like this. Maybe that is what the patent examiners need.

  • I'm thinking this would be very useful in the patent approval process, not just after the fact. Suppose it worked like this: The second you file a patent, it would be published. Before it could be approved, it would have to be public for some length of time, during which anyone could present prior art or arguments for "obviousness".

    That's brilliant. Why, change "the second" to "within 18 months after" and you just described the USPTO. All patent applications are published and public for some length of time before approval, during which anyone can present prior art or arguments for "obviousness".

    You knew that, right? I mean, you're not just griping about something without actually researching it, right?

  • I did the same thing (Score:3, Informative)

    by Trailer Trash ( 60756 ) on Tuesday January 05, 2010 @01:31AM (#30651560) Homepage

    I used to have a VAX assembly program called "er1e9", which computed e using base 1,000,000,000 numbers (which fit into 32-bit integers). I wrote that in the late 80's, and still have it around somewhere. Multiplying and dividing using the VAX instructions was fairly trivial with that format up to arbitrary lengths. It's a pretty obvious optimization, or at least it was for a college kid.

  • by Anonymous Coward on Tuesday January 05, 2010 @02:12AM (#30651754)

    Except for patent trolls, you know...

  • by TaoPhoenix ( 980487 ) <> on Tuesday January 05, 2010 @05:08AM (#30652696) Journal

    Sorry, sir, I changed my sig because of folks like you. It reads:

    Citation War - A1: Correct, NotCited. A2: Correct, Cited. B1: Wrong, NotCited B2: Wrong, Flawed Citation.

    Because all of slashdot seems to hide when I start a reply, you made me open seven tabs to compose this. But here we go.

    Section A - you vs. poster above you.

    You said: "[citations needed]very badly since you seem to be the only person on the entire internet to have ever heard any of these stories."

    Calling his comment some 75% correct, that makes your remark about 75% libel. [] ...libel (for written or otherwise published words)--is the communication of a statement that makes a claim, expressly stated or implied to be factual, that may give an individual, ... a negative image. It is usually.. a requirement that this claim be false and that the publication is communicated to someone other than the person defamed...

    Retire the Freudian acronym. This is a partial list of Slashdot Lawyers. If I were a lawyer I would be on my own list. I am not on that list. []

    Saying this is "too long - didn't read" tries to cover your fallacious post with a fallacious ad hominem attack. Your comment directly says his post was not long enough, so to discard the requested length below is a red herring.

    Section B - Poster's comment #2.

    "2. Aspirin was patented well after a similar process for making Salicylic Acid on an industrial scale was. The office decided, with no precidents, that making the same chemical in pure enough form that it was safe for medicinal use was novel. When challenged on it, the USPO said they were going through a bottle a day deciding patent claims and were not about to reject rewarding this claim no matter what the law said."

    "Salicylic Acid on an industrial scale"... also known as "Salicylic acid is commercially prepared from sodium salicylate, which is produced from sodium phenoxide and carbon dioxide at high pressure and temperature in the Kolbe-Schmitt reaction." []

    (In about the mid 1840's) ...Kolbe also synthesized salicylic acid and showed its value as a preservative. The process was named Kolbe synthesis (or Kolbe-Schmitt reaction)...

    Going to []

    Then, in 1853, French chemist Charles F. Gerhardt synthesized a primitive form of aspirin, a derivative of salicylic acid.

    In 1897 Felix Hoffmann, a German chemist working at the Bayer division of I.G. Farber, discovered a better method for synthesizing the drug.

    Going to []

    On March 6, 1899, Bayer registered Aspirin as a trademark. However, the German company lost the right to use the trademark in many countries as the Allies seized and resold its foreign assets after World War I. The right to use "Aspirin" in the United States (along with all other Bayer trademarks) was purchased from the U.S. government by Sterling Drug in 1918. However, even before the patent for the drug expired in 1917, Bayer had been unable to stop competitors from copying the formula and using the name elsewhere, and so, with a flooded market, the public was unable to recognize "Aspirin" as coming from only one manufacturer. Sterling was subsequently unable to prevent "Aspirin" from being ruled a genericized trademark in a U.S. federal court in 1921. Sterling was ultimately acquired by Bayer in 1994, but this did not rest

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