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Re: LANG: number range expressions

From: Dan Connolly <connolly@w3.org>
Date: 02 May 2002 13:53:20 -0500
To: Ziv Hellman <ziv@unicorn.com>
Cc: www-webont-wg@w3.org
Message-Id: <1020365600.30005.3037.camel@dirk>
On Thu, 2002-05-02 at 12:46, Ziv Hellman wrote:
> I was recently looking through some DAML+OIL documentation and I noticed
> that in order to, for example, constrain the property 'age' of a class
> Adult to being 17 or over, one needs the following syntax.
> 
> <daml:Class rdf:ID="Adult">
>  <daml:intersectionOf rdf:parseType="daml:collection">
>  <daml:Class rdf:about="#Person"/>
>     <daml:Restriction>
>       <daml:onProperty rdf:resource="#age"/>
>       <daml:hasClass 
> 	
> rdf:resource="http://www.daml.org/2001/03/daml+oil-ex-dt#over17"/>
>     </daml:Restriction>
>   </daml:intersectionOf>
> </daml:Class>
> 
> <xsd:simpleType name="over17">
>   <!-- over17 is an XMLS datatype based on decimal -->
>   <!-- with the added restriction that values must be >= 17 -->
>   <xsd:restriction base="xsd:decimal">
>   <xsd:minInclusive value="17"/>
>   </xsd:restriction>
> </xsd:simpleType>

In the course of the design of DAML+OIL, I suggested incorporating
XML Schema datatype facets into RDF/DAML+OIL; it might look
like this...

<rdf:RDF
    xmlns:dt="http://www.w3.org/2001/XMLSchema#"
    xmlns:ex="http://example/vocab#"
    xmlns:ont="http://www.daml.org/2001/03/daml+oil#"
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">

    <rdfs:Class rdf:about="http://example/vocab#Adult">
        <ont:intersectionOf rdf:parseType="ont:collection">
          <rdfs:Class rdf:about="http://example/vocab#Person"/>
          <ont:Restriction>
            <ont:hasClass rdf:parseType="Resource">
              <ont:intersectionOf rdf:parseType="ont:collection">
                <rdfs:Class
rdf:resource="http://www.w3.org/2001/XMLSchema#decimal"/>
                <rdfs:Class>
                  <dt:minInclusive>17</dt:minInclusive>
                </rdfs:Class>
              </ont:intersectionOf>
            </ont:hasClass>
            <ont:onProperty rdf:resource="http://example/vocab#age"/>
          </ont:Restriction>
        </ont:intersectionOf>
    </rdfs:Class>
</rdf:RDF>

or something like that.

But the group decided to keep the datatypes and the rest of the universe
of discourse separate, and this was one of the related consequences.

I have raised the issue of splitting datatypes out...
http://www.w3.org/2001/sw/WebOnt/webont-issues.html#5.1-Uniform-treatment-of-literal/data-values

But maybe this is worth a separate issue.

In the RDF Core WG's discussions about datatypes, I recently
suggested we include facets in the design...

  # user-defined datatype (facet) support needed?
  Dan Connolly (Tue, Apr 30 2002) 
  http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Apr/0547.html



[...]
> Will OWL inherit this type of behaviout from DAML+OIL?

Unless somebody raises an issue and we decide to resolve
the issue by changing it, yes.

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Thursday, 2 May 2002 14:54:00 GMT

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