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Re: Why do you want to do that?

From: Richard H. McCullough <rhm@pioneerca.com>
Date: Wed, 13 Aug 2008 18:36:26 -0700
Message-ID: <073B5E016D4E4891BD352EA3E6BCEA42@rhm8200>
To: "Michael Schneider" <schneid@fzi.de>, "Frank Manola" <fmanola@acm.org>
Cc: "SWIG" <semantic-web@w3.org>, "KR-language" <KR-language@YahooGroups.com>

Hi Michael
See below.

Dick McCullough
Ayn Rand do speak od mKR done;
mKE do enhance od Real Intelligence done;
knowledge := man do identify od existent done;
knowledge haspart proposition list;

----- Original Message ----- 
From: "Michael Schneider" <schneid@fzi.de>
To: "Frank Manola" <fmanola@acm.org>
Cc: "SWIG" <semantic-web@w3.org>; "Richard H. McCullough" 
Sent: Wednesday, August 13, 2008 4:57 PM
Subject: RE: Why do you want to do that?

> Hi Frank!
> Frank Manola wrote:
>>There aren't any classes in RDF (per se);  in RDFS there are classes,
>>and they can be treated as individuals (which is where we came in,
>>more or less).
> As a minor remark, I think it's easier to understand the situation of
> classes in RDFS, if one states the above sentence the other way around: In
> RDFS there are individuals (aka resources), and some of them can be 
> treated
> as classes, namely those which happen to have a class extension associated
> with them. Analog, some individuals have a property extension associated
> with them, and are therefore properties. An individual may even act as 
> both,
> a class *and* a property, if it has both a class extension and a property
> extension associated.

But in any case (as you say), all classes and
> properties are individuals, which exist in the RDFS universe, i.e. the
> domain of discourse.
***** This is an unnecessary "corruption" of the concept hierarchy.
Once again, the simple alternative is to use sets.
all class ismem ClassSet;
all property ismem PropertySet;
all individual ismem IndividualSet;
Except for the last line above,
x being a member of a set does NOT make x an individual.

In an appropriate context, you might view a property as
an individual.  For example
    John Doe has happy;
But in other contexts, it seems better to view a property
as a Class.  For example
    John Doe has gender = male;
These examples correspond to the hierarchy fragment:

begin hierarchy example;
/    i:happy;
/    gender;
//        i:male;
end hierarchy example;
>>That is, in RDFS a class is a resource (like
>>everything else that can be referred to in RDFS), and resources can be
>>the subjects of triples.
> Cheers,
> Michael
Received on Thursday, 14 August 2008 01:37:30 UTC

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