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RE: Are properties from a context-constrained class inherited by subclasses?

From: Hart, Lewis <lewishart@att.com>
Date: Thu, 22 May 2003 10:54:21 -0400
Message-ID: <4E4858A8C481D5119DA100B0D0796B8203B92B80@thumper.va.grci.com>
To: "Roger L. Costello" <costello@mitre.org>
Cc: www-rdf-interest@w3.org

> -----Original Message-----
> From: Roger L. Costello [mailto:costello@mitre.org]
> Sent: Wednesday, May 21, 2003 5:05 PM
> To: www-rdf-interest@w3.org
> Cc: Costello,Roger L.
> Subject: Are properties from a context-constrained class inherited by
> subclasses?
> 
> 
> 
> Hi Folks,
> 
> Suppose that I have this class heirarchy:
> 
>         River
>            |
>       Flueve
>           |
>        Blah
> 
> Suppose that the property, emptiesInto, has a domain of River:
> 
>      <owl:ObjectProperty rdf:ID="emptiesInto">
>            <rdfs:domain rdf:resource="#River"/>
>            <rdfs:range rdf:resource="#BodyOfWater"/>
>      </owl:ObjectProperty>
> 
> Suppose the Flueve constrains emptiesInto to have a range of #Sea:
> 
>      <owl:Class rdf:ID="Flueve">
>          <rdfs:subClassOf rdf:resource="#River"/>
>           <rdfs:subClassOf>
>                 <owl:Restriction>
>                         <owl:onProperty rdf:resource="#emptiesInto"/>
>                         <owl:allValuesFrom rdf:resource="#Sea"/>
>                 </owl:Restriction>
>           </rdfs:subClassOf>
>      </owl:Class>
> 
> Question: what is the range of emptiesInto when used in the Blah
> Class?   /Roger
> 
> 

Maybe this is a simple minded way of looking at it, but the range of
emptiesInto is BodyOfWater. Ranges are global, the fact that Flueve resticts
the values allowed for instances of emptiesInto which have instances of
Flueve as their subject does not, in my mind, change the range of
emptiesInto.  

The 'effective range' of emptiesInto for Flueve could be said to be Sea,
even without knowing what the actual range is, and similarly for Blah. 

- Lewis

Lewis L Hart 
Chief Scientist - Intelligent Agent Systems
------------------------------------------
AT&T Government Solutions lewishart@att.com
1900 Gallows Rd.       Voice (703) 506-5938
Vienna, Va 22182         Fax (703) 556-4261
Received on Thursday, 22 May 2003 11:07:01 GMT

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