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,c42dbf68f5320193 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-05-09 19:37:59 PST Path: archiver1.google.com!postnews1.google.com!not-for-mail From: dewar@gnat.com (Robert Dewar) Newsgroups: comp.lang.ada Subject: Re: Turing-undecidable languages (OT) Date: 9 May 2002 19:37:58 -0700 Organization: http://groups.google.com/ Message-ID: <5ee5b646.0205091837.6e1a7ea9@posting.google.com> References: <7mWB8.6827$0z6.115522658@newssvr21.news.prodigy.com> NNTP-Posting-Host: 205.232.38.14 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1020998279 4551 127.0.0.1 (10 May 2002 02:37:59 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 10 May 2002 02:37:59 GMT Xref: archiver1.google.com comp.lang.ada:23814 Date: 2002-05-10T02:37:59+00:00 List-Id: chris.danx@ntlworld.com (Danx) wrote in message news:... > "Chad R. Meiners" wrote in message news:... > > Does that mean that if any problem cannot be expressed > recursively, then no program can be coded to solve it? > In other words, any problem that can be solved without > recursion, can also be expressed using recursion and any > problem that cannot be solved by recursion cannot be > solved by a computer? Oh dear! Another terminology confusion. Recursively decidable means that an algorithm can be written in a normal recursive formalism (e.g. lambda calculus). It has little to do with the use of "recursion" in a procedural language. Think of it as just meaning (programmable in a normal programming language) and you will not be far off.