From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,d2c21e8238e985b5 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-05-27 16:52:15 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news-out.nuthinbutnews.com!propagator-sterling!news-in.nuthinbutnews.com!newsfeed.nyc.globix.net!news.stealth.net!news.stealth.net!news-east.rr.com!chnws02.ne.ipsvc.net!cyclone.ne.ipsvc.net!24.128.8.70!typhoon.ne.ipsvc.net.POSTED!not-for-mail Message-ID: <3CF2C6AF.60607@attbi.com> From: "Robert I. Eachus" Organization: Eachus Associates User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.4.1) Gecko/20020314 Netscape6/6.2.2 X-Accept-Language: en,pdf MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Extended modal types References: <3CEDFF90.B94D7E32@yahoo.com> <5ee5b646.0205250757.60c9715a@posting.google.com> <874rgwt6jf.fsf@deneb.enyo.de> <3CF1BE0C.8020704@attbi.com> <87elfyb0iz.fsf@deneb.enyo.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 27 May 2002 23:47:59 GMT NNTP-Posting-Host: 24.61.239.24 X-Complaints-To: abuse@attbi.com X-Trace: typhoon.ne.ipsvc.net 1022543279 24.61.239.24 (Mon, 27 May 2002 19:47:59 EDT) NNTP-Posting-Date: Mon, 27 May 2002 19:47:59 EDT Xref: archiver1.google.com comp.lang.ada:24856 Date: 2002-05-27T23:47:59+00:00 List-Id: Florian Weimer wrote: > The modulus has to be static, that's why modular types aren't > extremely useful even in this context. You are probably thinking of public-key encryption where the keys and modulii are too big for ordinary modular types anyway. I was thinking of many algorithms that use modular arithmetic to introduce non-linearity, for example multiplying two four-bit nibbles mod 17. In cases like this, the modulus is a static part of the algorithm definition, and needs to be prime for invertability. Similarly, hashing tables often use the sum of the character values mod the size of the hash table to generate a hash location.