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Re: Need example of a River class being used as an individual ... anyone?

From: Leo Obrst <lobrst@mitre.org>
Date: Mon, 10 Mar 2003 19:57:11 -0500
Message-ID: <3E6D3467.2718239@mitre.org>
To: David Martin <martin@ai.sri.com>
Cc: "Roger L. Costello" <costello@mitre.org>, www-rdf-logic@w3.org

For the historical record, Chris Welty has an old (1995) paper on this topic:
Welty, Chris and Ferrucci, Dave. 1994. What's in an Instance? RPI Computer
Science Technical Report. Available in [HTML] [PDF]. Off his home page:

Chris originally argued for OWL having a class as instance construct.


David Martin wrote:

> In the work on DAML-S, we are using classes as individuals in, I think, a
> very compelling way, which is somewhat reminiscent of the AirlineFlight
> example (discussed in other recent messages on this list).
> In brief, we model a process as the class of its occurrences.  For example,
> a process called BuyBook, associated with an online retail Web service,
> would be represented as a *subclass* (not an instance) of
>     http://www.daml.org/services/damls/0.7/Process.daml#Process
> A specific occurrence/execution/invocation/instantiation of BuyBook (say,
> John Doe buying "war and peace" using credit card cc01) is an *instance* of
> BuyBook.
> Of course, we need to say many interesting things about BuyBook, some of
> which are modelled quite nicely using basic DAML+OIL, and some of which
> aren't.  There are indeed places where we want to treat (and do treat)
> things like BuyBook as instances -- so that, for example, BuyBook can be
> mentioned as the object of some property instance.
> Conceptually, I believe the basic idea is quite nice, but it has caused us
> to stretch the limits of valid DAML+OIL in various ways, and we have had
> *lots* of discussion about the pros and cons of doing it this way.
> (Personally, I find it counterintuitive to always have to think about a
> process as the set of its occurrences.)
> I don't have time to elaborate any further at present, but you are invited
> to browse our examples and documents on our current release:
> http://www.daml.org/services/daml-s/0.7/
> Regards,
> David Martin
> DAML-S Coalition
> "Roger L. Costello" wrote:
> > Hi Folks,
> >
> > One of the "main" differences between OWL Full and OWL DL/Lite is that
> > in OWL Full a class may be treated as both an individual as well as a
> > class.  I am trying to create an example to demonstrate the use of a
> > class as an individual.  Specifically, an example to demonstrate the use
> > of a River class as an individual.  Here is how River is defined:
> >
> >     <rdfs:Class rdf:ID="River">
> >         <rdfs:subClassOf rdf:resource="#Stream"/>
> >     </rdfs:Class>
> >
> > Can you give me an example that shows this River class being used as an
> > instance?  Thanks!  /Roger

Dr. Leo Obrst  The MITRE Corporation
mailto:lobrst@mitre.org Intelligent Information Management/Exploitation
Voice: 703-883-6770 7515 Colshire Drive, M/S H305
Fax: 703-883-1379       McLean, VA 22102-7508, USA
Received on Monday, 10 March 2003 20:01:52 UTC

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