Re: Self pointer in limited record

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Wed, 05 Sep 2007 15:12:19 +0200, Jean-Pierre Rosen wrote:

> Dmitry A. Kazakov a �crit :

>> Yes, and you have to fix the point of view before you start to talk about
>> *an* abstraction. The abstraction can be "dog" or it can be "named thing,"
>> but it cannot be Spike.
>> 
> It seems that you really equate "abstraction" with "class". I agree that 
>   a class is a collection of objects, which is different from an 
> instance (= a single object).

No, I am using conventional meaning unspecific to programming. From

http://www.thefreedictionary.com/dict.asp?Word=abstraction

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

> 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.

None of standard meanings 1-6 can be thought on the basis of single
instance. 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?), 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.
Actually, there is no objects only these relations. This were unthinkable
to do on the basis of unique individual thing-in-itself.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de