- From: Reto Bachmann-Gmuer <reto@gmuer.ch>
- Date: Tue, 16 Sep 2003 20:51:33 +0200
- To: "Sbodio, Marco Luca" <marco.sbodio@hp.com>
- Cc: Dan Brickley <danbri@w3.org>, Art.Barstow@nokia.com, www-rdf-interest@w3.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (Darwin) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQE/Z1u1D1pReGFYfq4RAoFQAJ9h88BzxVvPSCGbfCwT9ollYnwjKgCgl0Gp 88GTS9Fs7sC7nX0sEAmZZBs= =I8rP -----END PGP SIGNATURE-----
Received on Tuesday, 16 September 2003 14:52:49 UTC