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Re: daml:item

From: Bijan Parsia <bparsia@isr.umd.edu>
Date: Wed, 16 Jul 2003 07:55:39 -0400
Cc: public comments <public-webont-comments@w3.org>
To: Jim Hendler <hendler@cs.umd.edu>
Message-Id: <6B95368B-B784-11D7-A324-0003936A0B26@isr.umd.edu>
I accept this outcome given with two provisos:

	1) Some mention goes in the "Changes from DAML+OIL" section:
		http://www.w3.org/TR/owl-ref/#appD
	2) It's made clear that such manipulation of lists puts one in OWL 
full. I'm finding that many people are rather surprised by that fact.

Cheers,
Bijan Parsia.

On Tuesday, July 15, 2003, at 09:35 PM, Jim Hendler wrote:

> At 7:45 PM -0400 5/9/03, Bijan Parsia wrote:
> >This could be an RDF issue, but given OWL's relationship to DAML+OIL, 
> I think it could reasonably be handled by WebOnt.
> >
> >DAML+OIL had daml:item. While not strictly necessary, i've been 
> encountering a fair number of DAML+OIL ontologies which use it, and 
> the alternative formulations (e.g., for typed lists) is fairly 
> cumbersome.
> >
> >So, I'd like it added back in.
> >
> >Cheers,
> >Bijan Parsia.
>
>
> Bijan-
>  Thanks for your email raising the issue of restoring daml:item.  The 
> list constructors were a difficult issue as they impacted both the RDF 
> Core and Web Ontology Working Groups, and the issue of whether to 
> include an "item" construct was considered by both.  Given the final 
> resolution, not to require it in RDF, the WebOnt WG was resistant to 
> adding it into OWL [1]. However, we did agree that you make a good 
> point about needing to be able to restrict the members of a list to a 
> class, and that the means to do that is not obvious.  We therefore are 
> adding the following example:
>
> >   <rdfs:Class rdf:ID="OperaList">
> >     <rdfs:subClassOf rdf:resource="&rdf;List"/>
> >     <rdfs:subClassOf>
> >       <Restriction>
> >         <onProperty rdf:resource="&rdf;first"/>
> >         <allValuesFrom rdf:resource="#Opera"/>
> >       </Restriction>
> >     </rdfs:subClassOf>
> >     <rdfs:subClassOf>
> >       <Restriction>
> >         <onProperty rdf:resource="&rdf;rest"/>
> >         <allValuesFrom rdf:resource="#OperaList"/>
> >       </Restriction>
> >     </rdfs:subClassOf>
> >   </rdfs:Class>
>
> to the reference document (with accompanying text currently being 
> produced - see the editor's draft).
>
>  Please let us know if this is adequate in meeting your comment
>  Jim Hendler for Web Ont WG
> [1] http://lists.w3.org/Archives/Public/www-webont-wg/2003Jul/0069.html
>
> -- 
>
> Professor James Hendler                       hendler@cs.umd.edu
> Director, Semantic Web and Agent Technologies        301-405-2696
> Maryland Information and Network Dynamics Lab.     301-405-6707 (Fax)
> Univ of Maryland, College Park, MD 20742     *** 240-277-3388 (Cell)
> http://www.cs.umd.edu/users/hendler      *** NOTE CHANGED CELL NUMBER 
> ***
Received on Wednesday, 16 July 2003 07:50:30 GMT

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