- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Thu, 13 Mar 2003 06:46:34 -0500 (EST)
- To: lichangq@comp.nus.edu.sg
- Cc: www-rdf-logic@w3.org
From: "Li Changqing" <lichangq@comp.nus.edu.sg> Subject: problem of DAML+OIL Date: Thu, 13 Mar 2003 18:28:21 +0800 > hi Sir/Mdm > > I have two questions about the DAML+OIL: > > in the animal ontology example specified by http://www.daml.org/2001/03/daml+oil-ex about the "daml:collection": > > <daml:Class rdf:about="#Person"> > <rdfs:comment>every person is a man or a woman</rdfs:comment> > <daml:disjointUnionOf rdf:parseType="daml:collection"> > <daml:Class rdf:about="#Man"/> > <daml:Class rdf:about="#Woman"/> > </daml:disjointUnionOf> > </daml:Class> > > The first question is:why did you use the "rdf:about" to refer to "#Man" > and "#woman"; why didn't you use "rdf:resource" to refer to "#Man" and > "#woman"? RDF/XML syntax is rather difficult to understand, as it uses many shorthand notations. Shorthand notations like <daml:Class rdf:about="#Man"/> are used when you have a member of a class (daml:Class in this case) and want to refer to an instance of the class (#Man in this case). Shorthand notations like <ex:friend rdf:resource="#Mary"/> are used when you want to specify a value (#Mary in this case) for a property (ex:friend in this case). > Can I use "rdf:resource" to refer to "#Man" and "#woman"? Here you can't because you need to provide an object (#Man), not a property and its value. > And the > second question is:can I use "rdf:Seq" here instead of "daml:collection", > since i want to union the the ordered members, such as the author of a > book, but "daml:collection" is not with members ordered. This would not work. First, DAML+OIL (and also OWL) do not use rdf:Seq at all, because of various problems with rdf:Seq and the other RDF container vocabulary. Second, union is inherently unordered so there is no reason to use a construct that explicitly uses order. > Thanks! > Best regards > > Changqing Li Peter F. Patel-Schneider Bell Labs Research Lucent Technologies
Received on Thursday, 13 March 2003 06:47:15 UTC