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,b78c363353551702
X-Google-NewGroupId: yes
X-Google-Attributes: gida07f3367d7,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Received: by 10.68.223.40 with SMTP id qr8mr12500639pbc.0.1341563406802;
        Fri, 06 Jul 2012 01:30:06 -0700 (PDT)
Path: 
 l9ni11017pbj.0!nntp.google.com!news2.google.com!news.glorb.com!newsfeed.straub-nv.de!noris.net!newsfeed.arcor.de!newsspool1.arcor-online.net!news.arcor.de.POSTED!not-for-mail
Date: Fri, 06 Jul 2012 10:30:01 +0200
From: Georg Bauhaus <rm.dash-bauhaus@futureapps.de>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7;
 rv:13.0) Gecko/20120614 Thunderbird/13.0.1
MIME-Version: 1.0
Newsgroups: comp.lang.ada
Subject: Re: about the new Ada 2012 pre/post conditions
References: <jrsjr7$uuo$1@speranza.aioe.org>
 <1bbvp3ghpjb5s.1go1s1qvcmagh$.dlg@40tude.net>
 <4fe76fad$0$9507$9b4e6d93@newsspool1.arcor-online.net>
 <1jt8vhzxfrv2i.eohce4d3rwx1$.dlg@40tude.net>
 <4fe83aaa$0$6624$9b4e6d93@newsspool2.arcor-online.net>
 <1pkfv0tiod3rn$.onx6dmaa3if9$.dlg@40tude.net>
 <Pine.LNX.4.64.1206251438390.12735@medsec1.medien.uni-weimar.de>
 <1i1mp8xs3vtl2.1oc4m66qtfgzq.dlg@40tude.net>
 <Pine.LNX.4.64.1206251734140.12735@medsec1.medien.uni-weimar.de>
 <bdpvyb9h7rvt.zbq0kbiq72wj.dlg@40tude.net>
 <Pine.LNX.4.64.1206261316320.22921@medsec1.medien.uni-weimar.de>
 <xmybo646240w$.13rwa9qwsliyp$.dlg@40tude.net> <jstvu4$jh4$1@munin.nbi.dk>
 <a555h2psfssb$.1be3awg0xbewa.dlg@40tude.net> <jt2rjm$vhe$1@munin.nbi.dk>
 <33crfw5vkxoh$.kz5mq75s36ee.dlg@40tude.net>
 <43e4637c-3337-4d99-be45-20e054e5a203@googlegroups.com>
 <6ua1uo9zmkjn$.1tmqyzmetx71u$.dlg@40tude.net>
 <4ff6969e$0$9514$9b4e6d93@newsspool1.arcor-online.net>
 <1xkiqefb6watw.10fvt344m3c4g$.dlg@40tude.net>
In-Reply-To: <1xkiqefb6watw.10fvt344m3c4g$.dlg@40tude.net>
Message-ID: <4ff6a20a$0$9525$9b4e6d93@newsspool1.arcor-online.net>
Organization: Arcor
NNTP-Posting-Date: 06 Jul 2012 10:30:02 CEST
NNTP-Posting-Host: 2120b03a.newsspool1.arcor-online.net
X-Trace: 
 DXC=XJ;ONQ9J=\Z5TOT9_N5i<Vic==]BZ:af^4Fo<]lROoRQnkgeX?EC@@P@eiPY3A=egUPCY\c7>ejVX9O]nZ9K^f@R[@Y<ZFQL1bP
X-Complaints-To: usenet-abuse@arcor.de
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Date: 2012-07-06T10:30:02+02:00
List-Id: <comp.lang.ada>

On 06.07.12 10:05, Dmitry A. Kazakov wrote:
> On Fri, 06 Jul 2012 09:41:18 +0200, Georg Bauhaus wrote:
>
>> On 05.07.12 21:55, Dmitry A. Kazakov wrote:
>>> On Thu, 5 Jul 2012 12:11:57 -0700 (PDT), Adam Beneschan wrote:
>>>
>>>> On Thursday, July 5, 2012 12:48:30 AM UTC-7, Dmitry A. Kazakov wrote:
>>>>
>>>>> Putting it even simpler. What is the effect of:
>>>>>
>>>>>      sqrt (-1.0)
>>>>>
>>>>> No effect? Any effect?
>>>>
>>>> This looks like an imaginary problem to me, not a real one.
>>>
>>> What problem? It was a simple question illustrating absurdity of the idea.
>>
>> Actually, a negative argument passed to sqrt is illustrating proper DbC
>> well. One famous example is Ariane 4, (4), that's the number four.
>
> If sqrt (-1.0) has no effect,

First, in a DbC correct program, sqrt(r) where r < 0.0 does not occur.

> what made Ariane to explode?

The engineers though the didn't have to re-read the contract
for Ariane 4 when moving the software to Ariane 5.

> Exploding is not an effect, right?

Wrong.