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-Thread: 103376,1d295367cf0b8c48 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news4.google.com!newsfeed2.dallas1.level3.net!news.level3.com!bos-service1.raytheon.com!dfw-service2.ext.ray.com.POSTED!53ab2750!not-for-mail From: Jeffrey Carter User-Agent: Mozilla Thunderbird 1.0.6 (Windows/20050716) X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: loop variant in SPARK ADA References: <1127121942.777976.45330@f14g2000cwb.googlegroups.com> <1127236537.057857.142300@g49g2000cwa.googlegroups.com> <1127270950.314911.66510@f14g2000cwb.googlegroups.com> In-Reply-To: <1127270950.314911.66510@f14g2000cwb.googlegroups.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Message-ID: Date: Wed, 21 Sep 2005 10:31:58 -0700 NNTP-Posting-Host: 147.24.111.90 X-Complaints-To: news@ext.ray.com X-Trace: dfw-service2.ext.ray.com 1127323918 147.24.111.90 (Wed, 21 Sep 2005 12:31:58 CDT) NNTP-Posting-Date: Wed, 21 Sep 2005 12:31:58 CDT Organization: Raytheon Company Xref: g2news1.google.com comp.lang.ada:5006 Date: 2005-09-21T10:31:58-07:00 List-Id: Constantin Porphyrogenete wrote: > > "Nevertheless, it is all too easy to > forget to think about the problem of termination and > to conclude that a subprogram is correct just because > all the verification conditions are true." I suspect this refers to the general concept of correctness proofs. The correctness proofs in SPARK are technically incomplete proofs because they don't prove termination in general; in other words, they haven't solved the halting problem. -- Jeffrey Carter "Now go away or I shall taunt you a second time." Monty Python and the Holy Grail E-mail: jeffrey_r_carter-nr [commercial-at] raytheon [period | full stop] com