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Re: Relation between OWL and OWL-S

From: Bijan Parsia <bparsia@isr.umd.edu>
Date: Sun, 28 Nov 2004 17:30:41 +0900
Message-Id: <CA39F3C1-4117-11D9-B962-000D93C1F7A6@isr.umd.edu>
Cc: public-sws-ig@w3.org
To: Drew McDermott <drew.mcdermott@yale.edu>

On Nov 27, 2004, at 12:51 PM, Drew McDermott wrote:

>> [Daniela Claro]
>> Thus my question is how can I differentiate two individuals 
>> (services) like
>> river bank and economical bank in OWL-S? Actually how can I 
>> differentiate
>> two ambiguous individuals (services) in OWL-S?
>
> I think you are still confused about where natural language ends and
> internal representation begins.

"Formal" representations? There's not a real sense in which an OWL 
document is *internal* to anything, in most respects.

>   Internally all we have to do is use
> two different symbols, and the two entities are "differentiated."

In OWL, this is necessary but not sufficient. You need to assert or 
imply a differentFrom in order for them to be required to be distinct 
(although they will not be required to be the same absent an asserted 
or implied sameAs; in most cases, differentiation of distinctly named 
individuals is contingent).

> (The two names can be made different just by having one be
> fluvial:bank and the other be mercantile:bank.)  We can give them
> different properties, but a KR system can believe two entities are
> different even if it doesn't know any properties that differentiate
> them.

Yep, at least in many, as we have explicit inequality. What we don't 
have is the Unique Name Assumption.

> Or we can avail ourselves of a really simple difference;
> for instance, we can declare that economic_entity is disjoint from
> geographic_entity, so all pairs of objects drawn from economic_entity
> x geographic_entity are given distinguishing features, because one has
> the feature "is an economic_entity" and the other has the incompatible
> feature "is a geographic_entity".
[snip]

or just assert that the two individuals are distinct.

Cheers,
Bijan Parsia.
Received on Sunday, 28 November 2004 08:30:43 GMT

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