RE: Mersenne: Re: The Second Mersennium Behind Us, How Now For MyriadThe Third?
" Dickens applied for the patent in October 1996 " I was using windowing in 1987, so his patent is invalid (prior invention). The problem now becomes, will these companies choose to challenge the patent in court, spending millions of dollars, or will each company alone figure it's cheaper to pay this guy than to pay their lawyers. Apparently, that's been the tactic for many other similar "patent" cases lately. What the article termed "submarine patents" for their stealth. Sad...isn't it? Let's all be thankful that neither Lucas nor Lehmer decided to patent their formula! :-) _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: RE: The Second Mersennium Behind Us, How Now For Myriad The Third?
I read a few days ago that the patent office is considering withdrawing the patent. It was stupid to grant it in the first place, but what is the effect if patents granted can be withdrawn (as has happened in a few other cases)? At 12:52 AM 1/12/00 -0700, you wrote: " Dickens applied for the patent in October 1996 " I was using windowing in 1987, so his patent is invalid (prior invention). The problem now becomes, will these companies choose to challenge the patent in court, spending millions of dollars, or will each company alone figure it's cheaper to pay this guy than to pay their lawyers. Apparently, that's been the tactic for many other similar "patent" cases lately. What the article termed "submarine patents" for their stealth. Sad...isn't it? Let's all be thankful that neither Lucas nor Lehmer decided to patent their formula! :-) _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: RE: The Second Mersennium Behind Us, How Now For Myriad The Third?
It was stupid to grant it in the first place, but what is the effect if patents granted can be withdrawn (as has happened in a few other cases)? basically, it will be as if it was never issued. The ex-patent-holder will be sitting there with egg on his face, and quite likely a candidate for lawsuits from anyone foolish enough to have paid him royalties on the patent which is no longer valid. just desserts if you ask me. We need a few precendents for strong deterrents to discourage future grandstanding like this. -jrp _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: The Second Mersennium Behind Us, How Now For MyriadThe Third?
It looks like what we've done is turn the Y2K bug into a couple of dozen smaller bugs. I wonder if anyone is keeping track of the various dates the new bugs will pop up? -Original Message- From: Tony Forbes [mailto:[EMAIL PROTECTED]] Sent: Tuesday, January 11, 2000 6:03 PM To: Mersenne@Base. Com Subject: Re: Mersenne: The Second Mersennium Behind Us, How Now For MyriadThe Third? Aaron Blosser [EMAIL PROTECTED] writes Dunno 'bout all that, but another problem was that in order to do a "quick and dirty" fix of the Y2K problem, a good number of people implemented windowing. Some used a window of 1930-2029 (which most Microsoft software uses to interpret 2 digit years), some used 1940-2039, etc. That gives those idiots another 29 years to fix the software the right way. One software company I know of is using a window of 1948-2047. So they could have a date problem in 2048. Surely this is the real 'Y2K bug'. -- Tony _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: New Prime95 Setup Program
Happy new year to everyone, Thanks to Wise Solution's generous donation of their InstallMaker program, http://www.wisesolutions.com, and Geoffrey Faivre-Malloy's programming efforts, Prime95 now has a fancy setup program! There is no need to upgrade (prime95.exe did not change), but if you are curious you can download it from http://www.mersenne.org/freesoft.htm Regards, George _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Why 2K?
Jud McCranie wrote: This is getting off topic, but: The criteria for something to be patentable is that the average practitioner in the field wouldn't think of it. So it boils down to whether the average programmer would think of windowing, given the problem. Well, that's the major criterion (non-obviousness) if no one has explicitly demonstrated or patented a similar thing previously... " Dickens applied for the patent in October 1996 " I was using windowing in 1987, so his patent is invalid (prior invention). ...in that case windowing is considered "prior art," and the patent is invalid on its face. Jud, assuming you have reasonable supporting documentation for your use of windowing prior to 1996, you should consider sending it to the U.S. patent and trademark office, http://www.uspto.gov (even if you have no desire to attempt to patent it - clearly, showing that you merely thought of it before 1996 in order to invalidate Joe Schmoe's patent is much easier than proving that you thought of it before anyone else did and seeking a patent yourself). Note that prior art is most easily established via publication, public use or sale - if you only wrote a windowing script for your own use, it may be more difficult to prove. From a programming perspective, my own top "why 2K" question is this this: even given that the person(s) who first used a mere 2 characters to store the year had good reason (e.g. severely limited computer memory) to do so, why didn't they use those 2 precious bytes as a 2-byte integer? Had they done so, we'd be talking instead about the "Y32K" or "Y64K" bug, and even Microsoft might have had sufficient time to fix their software by then. :) -Ernst _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Re: Status of last discoverd prime
Paul van Grieken wrote: Last year there was a email about the new found prime. I could read there was a second check to see if it was really a prime. After that I did not see any result. Can someone tell me what the status is of the last found mersenne prime. just because I am curious about it. Hi, Paul: I'm not sure just what you mean by "After that I did not see any result." Nayan Hajratwala performed the run that found M6972593 to be prime using George's Prime95 code, and David Willmore confirmed it using my Mlucas code. Since two different codes running on two different types of hardware agree on the result, it is considered verified. Currently GIMPS still has several thousand exponents below 6972593 to finish testing, i.e. assuming no further primes are discovered amongst these, we still have several months to go before we can say with 99% confidence that there are no Mersenne primes between M3021377 and M6972593. (Although this seems likely, given that there are over 200,000 candidate exponents between 3021377 and 6972593, i.e. nearly 99% of these have been tested at least once, with no new primes found.) Best regards, Ernst _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Re: The Second Mersennium Behind Us...yeah more bad code
If the windowing is used correctly there is no reason why a system cannot go on "indefinitely" processing "current" info. The idea is tie the split date to the current date so that the window "slides" along. However, knowing what commercial programmers are like most will just do a dirty fix like WindowStartDate:='1/1/1997' or such like. I hate seeing numbers scattered through code obviously such programmers miss the point of sticking constants at the top of their source files or using initialisation files. This style applies also to number theoretical programs e.g. a "31" in one part of your program may not be a "31" for the same reason as a "31" in another part of the program - so why not call the first "ELEVENTH_PRIME" and the second "N_BITS_LESS_1" and declare them/calculate them accordingly at the top of the code. The advantage being that when you eventually get that 256 bit machine you have always dreamed of you do not have to re-write you're whole program ... catch my drift? Of course this does not work if you've unravelled lots of loops for speed - but honestly modern compilers should sort that one out for us or at least provide some mechanism where by you can say something like: "function MyFunction(my_var); inline for my_var=1 to MY_CONST; ..." I do not know if you can do this in C, I do not think it is possible with Pascal compilers - if not it should be made a feature of any serious compiler. Thoughts? -- Daniel W. Grace e-mail: [EMAIL PROTECTED] _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Re: The Second Mersennium...and sequences
I know that in Delphi (the best pascal for Windows) that there is a variable that specifies a century "window" around the "current" date so that two digit dates can be interpretted as "current". On the more relevant issue of storing Mersennes is this question and storing numbers from Mathematical series (particularly primes) in general is: Has anyone worked out an efficient way to compress the primes or prime exponents that produce prime Mersennes? Is such a method ever used to reduce the relevant patterns and then backtrack to find new conjectures or avenues for research? I would guess myself that with only 38 numbers there are too many possible compression algorithms, even if you reduced the possible space down by only considering "quick ones". However this might make for an interesting project if one considered primes of the form (2^n)k+/-1. Along similar lines, recently I was reading Hofstadters "Fluid Concepts Creative Analogies". In the book he shows an interesting project he worked on from an early age of counting triangular numbers between squares which inspired me to come up with the following questions: How many primes of the form (2^k)n +/- 1 with n1, k=3 are there between Mersenne primes? Or just: How many primes of the form (2^k)n - 1 with n1, k=3 are there between Mersenne primes? Any takers? -- Daniel W. Grace e-mail: [EMAIL PROTECTED] _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Why 2K?
On 12 Jan 00, at 15:48, [EMAIL PROTECTED] wrote: ...in that case windowing is considered "prior art," and the patent is invalid on its face. Jud, assuming you have reasonable supporting documentation for your use of windowing prior to 1996, you should consider sending it to the U.S. patent and trademark office, http://www.uspto.gov (even if you have no desire to attempt to patent it - clearly, showing that you merely thought of it before 1996 in order to invalidate Joe Schmoe's patent is much easier than proving that you thought of it before anyone else did and seeking a patent yourself). Note that prior art is most easily established via publication, public use or sale - if you only wrote a windowing script for your own use, it may be more difficult to prove. What about all the dialects of various languages which allow one to declared windowed arrays? (e.g. Microsoft QBASIC released circa 1988 allows e.g. DIM PROFITS (1984 TO 2018)) Or, sliding variable-size windowing has been in the TCP definition for at least twice as long as that. I think the reason no-one bothered to patent or copyright the idea of windowing is it is that it's so obvious ... From a programming perspective, my own top "why 2K" question is this this: even given that the person(s) who first used a mere 2 characters to store the year had good reason (e.g. severely limited computer memory) to do so, why didn't they use those 2 precious bytes as a 2-byte integer? COBOL programmers probably declared the year variable as PIC(99) - and a COBOL programmer has no direct means of knowing how that's stored in memory. (Note that PIC 99 USAGE COMPUTATIONAL (binary) would still require 7 bits whereas PIC 999 USAGE COMPUTATIONAL would require 10 bits. PIC 9(4) USAGE COMPUTATIONAL is as near as you can get to a 16-bit integer using COBOL but still only stores values - . Anyway, back in the '60s, lots of systems had word lengths based on multiples of 6 rather than of 8, so manipulating an explicit 16-bit integer would not neccessarily have been efficient! Note that, on an 8 bit machine, COBOL compilers would group together variables defined as PIC 99 and align them on byte boundaries, this actually gives quite reasonable packing makes arithmetic easy provided you have BCD arithmetic instructions. In fact, this is why modern processors retain BCD arithmetic - the instructions are hardly ever used, except by programs written in COBOL! Regards Brian Beesley _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Re: The Second Mersennium...and sequences
At 09:35 PM 1/12/99 +, Daniel Grace wrote: On the more relevant issue of storing Mersennes is this question and storing numbers from Mathematical series (particularly primes) in general is: Has anyone worked out an efficient way to compress the primes or prime exponents that produce prime Mersennes? I doubt that the Mersenne exponents can be compressed much. As far as a general prime list, there are several ways to save space. One is to store the gaps between primes instead of the primes themselves, and reconstruct the primes as you read through the list. One byte for the semi-difference suffices to fairly large primes. Another way is to use a bit vector indicating whether the given number is prime or not. Which method is best depends on the size of the list, and how you want to use the list. ++ | Jud McCranie | || | 137*2^197783+1 is prime! (59,541 digits, 11/11/99)| ++ _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Why 2K?
At 03:48 PM 1/12/00 EST, Ernst wrote: Jud McCranie wrote: This is getting off topic, but: The criteria for something to be patentable is that the average practitioner in the field wouldn't think of it. So it boils down to whether the average programmer would think of windowing, given the problem. Well, that's the major criterion (non-obviousness) if no one has explicitly demonstrated or patented a similar thing previously... " Dickens applied for the patent in October 1996 " I was using windowing in 1987, so his patent is invalid (prior invention). ...in that case windowing is considered "prior art," and the patent is invalid on its face. Jud, assuming you have reasonable supporting documentation for your use of windowing prior to 1996, you should consider sending it to the U.S. patent and trademark office, http://www.uspto.gov (even if you have no desire to attempt to patent it - clearly, showing that you merely thought of it before 1996 in order to invalidate Joe Schmoe's patent is much easier than proving that you thought of it before anyone else did and seeking a patent yourself). Note that prior art is most easily established via publication, public use or sale - if you only wrote a windowing script for your own use, it may be more difficult to prove. From a programming perspective, my own top "why 2K" question is this this: even given that the person(s) who first used a mere 2 characters to store the year had good reason (e.g. severely limited computer memory) to do so, why didn't they use those 2 precious bytes as a 2-byte integer? Had they done so, we'd be talking instead about the "Y32K" or "Y64K" bug, and even Microsoft might have had sufficient time to fix their software by then. :) -Ernst It wasn't so much the computer memory, Ernst, as it was the disk storage space. An insurance application record would have perhaps 6 dates within 100 bytes: date of applicant's birth, date application for insurance was taken, date of proposed enrollment, date the first premium was due, date the premium was received/recorded in the system, date of expiration if the payments stopped, and probably more. Saving the "century" field 6 times was 12 bytes saved in COBOL PIC 99 mode. Clever was the use of COBOL PIC XX as a COMPUTATIONAL field to store a date in 16 bits (which was the length of PIX XX). 7 bits for year since 2^7 = 128 so a year value up to 99 was stored there; 5 bits for day since 2^5 = 32 so a day value was stored there and 4 bits for month as 2^4 = 16 so a month value was stored there. Two bytes for a YEAR-MONTH-DAY value was great. Adding century was a bummer to this idea. The programmer had to have a REDEFINED PIC 99 COMP-4 of the PIC XX and then use a routine to extract three fields. As some may recall, the packed-digits format (COMP-3) was also used to store disk space on the file's record. IBM created/used this format to allow space savings. But the bottom line was that in the 1960's and 1970's, disk store space was expensive and saving it was worth the effort spent in more programming (people were cheaper that computers, in a way). Yes, memory was expensive and limited, but it was not the cause of the Y2K issue. No one in the late 1980's EVER believed that the PC would be as powerful as it is now, that disk storage would be as cheap, and that all these improvement would be in the home !! Only the 1.44 MB diskette of ten years ago remains the same. And I am delighted that MERSENNE.ORG lets me hunt for giant primes even if I never find one. _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Why 2K?
At 03:48 PM 1/12/00 EST, Ernst wrote: From a programming perspective, my own top "why 2K" question is this this: even given that the person(s) who first used a mere 2 characters to store the year had good reason (e.g. severely limited computer memory) to do so, why didn't they use those 2 precious bytes as a 2-byte integer? I think its due to punched cards. Reading and writing 2 digit dates on the punched card makes using PIC 99 COMPUTATIONAL inappropriate. Regards George P.S. Yes I'm old enough to have used punch cards. _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
