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Re: Enumeration in RDF

From: Reto Bachmann-Gmuer <reto@gmuer.ch>
Date: Tue, 16 Sep 2003 20:51:33 +0200
Message-ID: <3F675BB5.3020502@gmuer.ch>
To: "Sbodio, Marco Luca" <marco.sbodio@hp.com>
Cc: Dan Brickley <danbri@w3.org>, Art.Barstow@nokia.com, www-rdf-interest@w3.org

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Sbodio, Marco Luca wrote:

| As far as I know OWL has something that helps: owl:cardinality (see
http://www.w3.org/TR/2003/CR-owl-ref-20030818/#cardinality-def).
| "A restriction containing an owl:cardinality constraint describes a
class of all individuals that have exactly N semantically distinct
values (individuals or data values) for the property concerned, where N
is the value of the cardinality constraint"
|
| This allows you to express cardinality constraints on properties. The
OWL Web Ontology Language Reference (see above link) gives an example:
|
| <owl:Restriction>
|   <owl:onProperty rdf:resource="#hasParent" />
|   <owl:cardinality
rdf:datatype="&xsd;nonNegativeInteger">2</owl:cardinality>
| </owl:Restriction>
|
| which is a class of individuals that have exactly 2 parents.
|
| So I guess you can express what you want in OWL, but you need to put a
constraints on a property (in the above example "#hasParent").
|
So I guess you could restrain on
http://www.w3.org/2000/01/rdf-schema#member:

<rdfs:Class rdf:ID="BagSize4>
~  <rdfs:subClassOf
~   rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Bag"/>
~ <rdfs:subClassOf>
~  <owl:Restriction>
~   <owl:onProperty
~ 	rdf:resource="#http://www.w3.org/2000/01/rdf-schema#member" />
~   <owl:cardinality
~        rdf:datatype="&xsd;nonNegativeInteger">4</owl:cardinality>
~  </owl:Restriction>
~ </rdfs:subClassOf>
</rdfs:Class>


cheers,
reto
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Received on Tuesday, 16 September 2003 14:52:49 GMT

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