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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!feeder.erje.net!1.eu.feeder.erje.net!news-2.dfn.de!news.dfn.de!news.uni-weimar.de!medsec1.medien.uni-weimar.de!lucks From: Stefan.Lucks@uni-weimar.de Newsgroups: comp.lang.ada Subject: Re: {Pre,Post}conditions and side effects Date: Tue, 12 May 2015 22:52:02 +0200 Organization: Bauhaus-Universitaet Weimar Message-ID: References: <2430252d-52a1-4609-acef-684864e6ca0c@googlegroups.com> <0a718b39-ebd3-4ab5-912e-f1229679dacc@googlegroups.com> <9ee5e186-5aaa-4d07-9490-0f9fdbb5ca18@googlegroups.com> <87tww5296f.fsf@adaheads.sparre-andersen.dk> <871tj9dp5b.fsf@theworld.com> <87y4ktzldl.fsf@jester.gateway.sonic.net> NNTP-Posting-Host: medsec1.medien.uni-weimar.de Mime-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="8323329-1554116963-1431463923=:664" X-Trace: pinkpiglet.scc.uni-weimar.de 1431464324 26664 141.54.178.228 (12 May 2015 20:58:44 GMT) X-Complaints-To: news@pinkpiglet.scc.uni-weimar.de NNTP-Posting-Date: Tue, 12 May 2015 20:58:44 +0000 (UTC) X-X-Sender: lucks@debian In-Reply-To: <87y4ktzldl.fsf@jester.gateway.sonic.net> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) Xref: news.eternal-september.org comp.lang.ada:25850 Date: 2015-05-12T22:52:02+02:00 List-Id: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-1554116963-1431463923=:664 Content-Type: TEXT/PLAIN; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE On Tue, 12 May 2015, Paul Rubin wrote: > Stefan.Lucks@uni-weimar.de writes: >> pre =3D> (for I in 2 .. N-1 =3D> (N mod I /=3D0)) > > Of course that still doesn't prove that N is prime: you need a separate > proof that N has no divisors greater than N, and that proof has to > quantify over all the integers, so it's not executable at all. Stuff > like this is why formal methods are often less convenient than we'd > like. Good Point! ------ I love the taste of Cryptanalysis in the morning! ------ uni-weimar.de/de/medien/professuren/mediensicherheit/people/stefan-lucks --Stefan.Lucks (at) uni-weimar.de, Bauhaus-Universit=E4t Weimar, Germany-- --8323329-1554116963-1431463923=:664--