Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!feeder.erje.net!news.internetdienste.de!news.tu-darmstadt.de!news.belwue.de!rz.uni-karlsruhe.de!feed.news.schlund.de!schlund.de!news.online.de!not-for-mail From: Peter Pein Newsgroups: comp.soft-sys.math.maple Subject: Re: Mod Date: Mon, 23 May 2011 14:07:06 +0200 Organization: 1&1 Internet AG Lines: 30 Message-ID: References: <_dudnRR1uL-yX0TQnZ2dnUVZ_oGdnZ2d@wavecable.com> <93ucb2F9lmU1@mid.individual.net> NNTP-Posting-Host: p4fc21463.dip0.t-ipconnect.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: online.de 1306152427 27311 79.194.20.99 (23 May 2011 12:07:07 GMT) X-Complaints-To: abuse@einsundeins.com NNTP-Posting-Date: Mon, 23 May 2011 12:07:07 +0000 (UTC) User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.2.17) Gecko/20110414 Mnenhy/0.8.3 Thunderbird/3.1.10 In-Reply-To: <93ucb2F9lmU1@mid.individual.net> Xref: x330-a1.tempe.blueboxinc.net comp.soft-sys.math.maple:161 Am 23.05.2011 08:14, schrieb Axel Vogt: > Thomas D. Dean wrote: >> Maple 11 >> >> 1/3 mod 7 >> 5 >> (1/3) mod 7 >> 5 >> -2 mod 7 >> 5 >> >> How do I explain 1/3 mod 7 in terms of the definition? >> >> r = a mod n >> >> a = n*q + r >> >> >> tomdean > > Your input 1/3 is interpreted as "multiplicative inverse > of 3" and Maple answers that: 3*5 = 15 = 2*7 + 1 = 1 (7). > > Try to enter 1/2 mod 14. You will get "Error, the modular > inverse does not exist" so "mod" is not the "mod" I know? I would expect for any x < 14 that mod (x,14)=x and not an error-message. Should my professor for numbertheory be set on fire?