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

From: David Martin <martin@AI.SRI.COM>
Date: Mon, 10 Mar 2003 15:20:26 -0800
Message-ID: <3E6D1DBA.1E182499@ai.sri.com>
To: "Roger L. Costello" <costello@mitre.org>
CC: www-rdf-logic@w3.org

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
Received on Monday, 10 March 2003 18:19:57 GMT

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