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Re: Ways to restrict the properties a class may have?

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Mon, 01 Nov 2004 08:37:12 -0500 (EST)
Message-Id: <20041101.083712.40837234.pfps@research.bell-labs.com>
To: algermissen@acm.org, jalgermissen@topicmapping.com
Cc: cjp39@cam.ac.uk, www-rdf-interest@w3.org, b.fallenstein@gmx.de

From: Jan Algermissen <jalgermissen@topicmapping.com>
Subject: Re: Ways to restrict the properties a class may have?
Date: Fri, 29 Oct 2004 19:15:48 +0200

> "Peter F. Patel-Schneider" wrote:
> 
> > Huh?  Why would a system that checks to see if an inconsistency results
> > from a update and rejects such updates not satisfy your requirements?
> > 
> > For example,
> > 
> > ex:numberOfWindows rdfs:domain ex:somethingWithWindows .
> > ex:somethingWithWindows owl:disjointWith ex:employee .
> > 
> > ex:Jan rdf:type ex:employee .
> > 
> > ex:Jan numberOfWindows "5"^^xsd:int .
> > 
> > is inconsistent (in OWL) and an OWL reasoner can detect this.
> 
> Ah, I now see it. Of course what I want implies that all classes are
> disjoint and saying ex:somethingWithWindows owl:disjointWith ex:employee .
> is not an additional 'constraint' (which I first thought).

Hmm.  You probably *don't* want "all classes are disjoint", because that
would, for example, make person and student disjoint, which some people
think is not actually the case.  :-)

You are probably searching for something like "all classes are disjoint
unless there is some reason to not have them disjoint". which sounds nice
at first but can have unusual consequences.

[...]

> Jan Algermissen
> Consultant & Programmer	
> http://www.jalgermissen.com
Received on Monday, 1 November 2004 13:30:07 UTC

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