- From: Yuzhong Qu <yzqu@seu.edu.cn>
- Date: Wed, 26 Mar 2003 23:04:41 +0800
- To: "Roger L. Costello" <costello@mitre.org>
- Cc: <www-rdf-logic@w3.org>
I think they are different. In the second one, the property "serial" can be applied to the objects other than the gun. One more suggestion: The property "serial" should be a DatatypeProperty. Yuzhong Qu > > Thanks Peter. So you are saying that if I defined the Gun class like this: > > <owl:Class rdf:ID="Gun"> > <rdfs:subClassOf> > <owl:Restriction> > <owl:onProperty rdf:resource="#serial"/> > <owl:maxCardinality>1</owl:maxCardinality> > </owl:Restriction> > </rdfs:subClassOf> > </owl:Class> > > then the two forms would be equivalent? /Roger > > > "Peter F. Patel-Schneider" wrote: > > > From: "Roger L. Costello" <costello@mitre.org> > > Subject: Difference between cardinality=1 and FunctionalProperty? > > Date: Wed, 26 Mar 2003 06:39:07 -0500 > > > > > > > > Hi Folks, > > > > > > Aren't the below two forms essentially stating the same thing: > > > > > > <owl:Class rdf:ID="Gun"> > > > <rdfs:subClassOf> > > > <owl:Restriction> > > > <owl:onProperty rdf:resource="#serial"/> > > > <owl:cardinality>1</owl:cardinality> > > > </owl:Restriction> > > > </rdfs:subClassOf> > > > </owl:Class> > > > > > > <owl:ObjectProperty rdf:ID="serial"> > > > <rdfs:domain rdf:resource="#Gun"/> > > > <rdfs:range rdf:resource="&rdfs;#Literal"/> > > > </owl:ObjectProperty> > > > > > > VERSUS > > > > > > <owl:Class rdf:ID="Gun"/> > > > > > > <owl:FunctionalProperty rdf:ID="serial"> > > > <rdfs:domain rdf:resource="Gun" /> > > > <rdfs:range rdf:resource="&rdfs;#Literal"/> > > > </owl:FunctionalProperty> > > > > > > Both forms state that an instance of Gun must have exactly one value for > > > the serial property; e.g., > > > > > > <Gun rdf:ID="SmithWesson"> > > > <serial>ABCD</serial> > > > </Gun> > > > > > > Correct? /Roger > > > > > > > Not correct. Functional properties are only partial functional. Making > > functional properties be total functional would cause extreme problems. > > > > However, replacing cardinality with maxCardinality above would do the > > trick. > > > > Peter F. Patel-Schneider > > Bell Labs Research > > Lucent Technologies > > > > PS: It would be better to make the range of serial be xsd:string. > > >
Received on Wednesday, 26 March 2003 10:03:49 UTC