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=0.4 required=5.0 tests=BAYES_00,FORGED_MUA_MOZILLA autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,5412c98a3943e746 X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Received: by 10.68.135.231 with SMTP id pv7mr780154pbb.8.1331253962255; Thu, 08 Mar 2012 16:46:02 -0800 (PST) Path: h9ni4319pbe.0!nntp.google.com!news2.google.com!goblin2!goblin.stu.neva.ru!news.teledata-fn.de!newsfeed.arcor.de!newsspool4.arcor-online.net!news.arcor.de.POSTED!not-for-mail Date: Fri, 09 Mar 2012 01:44:01 +0100 From: Georg Bauhaus User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:10.0.2) Gecko/20120216 Thunderbird/10.0.2 MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Verified compilers? References: <9207716.776.1331054644462.JavaMail.geo-discussion-forums@ynaz38> <4edda5mav3cf$.149pbgyxl1wx5.dlg@40tude.net> <9rplcgF5a2U1@mid.individual.net> <1psd0g0womgxi.1sle7ol12x3d5.dlg@40tude.net> <9rsahhFmr3U1@mid.individual.net> In-Reply-To: Message-ID: <4f595251$0$7619$9b4e6d93@newsspool1.arcor-online.net> Organization: Arcor NNTP-Posting-Date: 09 Mar 2012 01:44:01 CET NNTP-Posting-Host: 6beffc0c.newsspool1.arcor-online.net X-Trace: DXC=@j=C:>BlIfD2jYf>V4L0gLic==]BZ:afN4Fo<]lROoRA<`=YMgDjhgB2A@5h?dhfKEPCY\c7>ejVH_QKZ4R[G69M252k>0:>ZkF X-Complaints-To: usenet-abuse@arcor.de Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Date: 2012-03-09T01:44:01+01:00 List-Id: On 08.03.12 21:40, Dmitry A. Kazakov wrote: > On Thu, 08 Mar 2012 20:02:25 +0200, Niklas Holsti wrote: >> How else could you explain why "2*3+4*5" means 26, and not 70, nor >> something else? > > Explain? It is a subject of proof. There are more than one way to do it. > BTW the "meaning" you are advocating for looks rather something like > 23*45*+. No! It must mean "at least zero twos followed by a three or more of these, with maybe fours coming next, and finally a five". + is clearly a macro. And, for proof, in which school did they ever teach that a star denotes multiplication? A Kleene star is a Kleene star. No! "2*3+4*5" must have a syntax error. What it really means is this: Python>>> "2"*3+"4"*5 '22244444' What? No! Dumb animal, this Python. The mathematical interpretation is obviously right: Perl-DB<1> print "2"*3+"4"*5 26 Excuse me, no! A Programming Language was there first, and it says, * 2*3+4*5 Inf Because, obviously, * 2*1027 Inf Uh, no, not any more. Are you guys still using that old APL dialect? Look at J for the real meaning: 2*3+4*5 46 Because 3+4*5 23 Nah! Ever since 1969, SNOBOL-4 clearly shows that 2*3+4*5 2*3+4*5 ^ stdin:1: *** Illegal character in element Because a string needs quotes around it, for one thing! Right, that's been known by Lispers for a long time: * 2*3+4*5 Error in KERNEL::UNBOUND-SYMBOL-ERROR-HANDLER: the variable 2*3+4*5 is unbound. [Condition of type UNBOUND-VARIABLE] Really, you can't remove the quotes from a string and expect it to have meaning? Look, all it means when output is just itself! SNOBOL4 (Version 3.11, May 19, 1975) Bell Telephone Laboratories, Incorporated OUTPUT = "2*3+4*5" END No errors detected in source program 2*3+4*5 Normal termination at level 0 -- > LISP * 2 + 3 * 4 + 5 2 * 2 * 3 * 3 * 4 * 4 * 5 * (QUIT)