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: 103376,5c89acd494ea9116 X-Google-Attributes: gid103376,public,usenet X-Google-Language: ENGLISH,ASCII Path: g2news2.google.com!news3.google.com!proxad.net!feeder1-2.proxad.net!news.in2p3.fr!in2p3.fr!oleane.net!oleane!hunter.axlog.fr!nobody From: Jean-Pierre Rosen Newsgroups: comp.lang.ada Subject: Re: Self pointer in limited record Date: Wed, 05 Sep 2007 18:25:29 +0200 Organization: Adalog Message-ID: References: <1183577468.034566.57830@n60g2000hse.googlegroups.com> <9fy1xoukz1e3$.h574sqmiauri$.dlg@40tude.net> <46d968ee$0$30368$9b4e6d93@newsspool4.arcor-online.net> <137iu0lr82dtb$.wqy3zjz2vr9q.dlg@40tude.net> <46d972e8$0$30384$9b4e6d93@newsspool4.arcor-online.net> <1alyfwaig93sk$.99oy269uon$.dlg@40tude.net> <46d9c138$0$4531$9b4e6d93@newsspool3.arcor-online.net> <1rt8kdcrj6tf.1qgvycc6vh357$.dlg@40tude.net> <46db2bf4$0$7699$9b4e6d93@newsspool2.arcor-online.net> <1188816674.2630.25.camel@kartoffel.vocalweb.de> <9cdmw7k85sey.85sb2t1bjefy$.dlg@40tude.net> <1mbajw59c3eir.jyl8bdp6qvj8.dlg@40tude.net> <1188850449.2630.60.camel@kartoffel.vocalweb.de> <1aza6nzawgcnm.sf76q4dvzw4n$.dlg@40tude.net> <46de8897$0$16115$9b4e6d93@newsspool1.arcor-online.net> <15hzyyy3soem0.12hn79bwy27zt$.dlg@40tude.net> <36wdoqy402nv$.14ugvmc6edxwu.dlg@40tude.net> NNTP-Posting-Host: mailhost.axlog.fr Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Trace: s1.news.oleane.net 1189011661 29405 195.25.228.57 (5 Sep 2007 17:01:01 GMT) X-Complaints-To: abuse@oleane.net NNTP-Posting-Date: Wed, 5 Sep 2007 17:01:01 +0000 (UTC) User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) In-Reply-To: <36wdoqy402nv$.14ugvmc6edxwu.dlg@40tude.net> Xref: g2news2.google.com comp.lang.ada:1757 Date: 2007-09-05T18:25:29+02:00 List-Id: Dmitry A. Kazakov a �crit : > 1. a concept or idea not associated with any specific instance; "he loved > her only in the abstract--not in person" > > 2. the act of withdrawing or removing something > > 3. the process of formulating general concepts by abstracting common > properties of instances > > 4. an abstract painting > > 5. preoccupation with something to the exclusion of all else > > 6. a general concept formed by extracting common features from specific > examples Interesting... >> But an abstraction (as I -and apparently others- understand it) is a >> reduced view of a real world *object*. > > This is close the position 2. Mine is under 1 and 6 and Georg's is under 3. Yes. This is also the ethymological meaning: abs-tractare (latin) means "to withdraw from" > None of standard meanings 1-6 can be thought on the basis of single > instance. 2 certainly can. The idea is that you cannot put "Spike the dog" into your computer; what you can do is put some characteristics of it in the form of data that are of interest from the point of view of your program. You therefore abstract away all the uninteresting properties. > The dictionary explicitly refers to "instances" and "examples." > Even treating abstraction exclusively as modeling with removing something > in order to model (though why couldn't we add something?) How could you have something in the model that is not in what you are modelling? > , even when > abstraction = moving from one substrate to another, one have to model not > only the object, but the relations it participates with other objects. But you can have relations between instances, not necessarily between classes. If I walk Spike, it is a relation between an instance of a human being and an instance of a dogan being :-) -- --------------------------------------------------------- J-P. Rosen (rosen@adalog.fr) Visit Adalog's web site at http://www.adalog.fr