I discovered a significant bug when dealing with SameAs and functional
properties. Here's the Java code:
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Iterator;
import com.hp.hpl.jena.ontology.*;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.reasoner.ValidityReport;
public class SameAsTest {
public static void main(String[] args) throws IOException {
OntModel m =
ModelFactory.createOntologyModel(OntModelSpec.OWL_DL_MEM_RULE_INF);
FileInputStream inStream = new FileInputStream("ontology/vehicle.owl");
m.read(inStream, null);
inStream.close();
String uriBase = m.getNsPrefixURI("");
OntClass vehCls = m.getOntClass(uriBase + "Vehicle");
Individual myCar = vehCls.createIndividual(uriBase + "/data/myCar");
DatatypeProperty wheels = m.getDatatypeProperty(uriBase + "numWheels");
// state that myCar has 4 wheels
myCar.addProperty(wheels, "4");
// do the same for another vehicle
Individual redCrv = vehCls.createIndividual(uriBase + "/data/redCrv");
redCrv.addProperty(wheels, "4");
// now add the fact that the redCrv and myCar are the same object
myCar.addSameAs(redCrv);
ValidityReport rept = m.validate();
for (Iterator<ValidityReport.Report> riter = rept.getReports(); riter
.hasNext();) {
ValidityReport.Report rep = riter.next();
System.out.println("ValRep: " + rep.getDescription());
}
}
}
The relevant ontology is attached to this message. The crucial thing is that
numWheels is a datatype property, with a max cardinality of 1 for the Vehicle
class.
When the two vehicles are linked via the SameAs property, the number of wheels
are also linked because of cardinality. However, sameAs doesn't allow datatype
values (literals) to be linked. It's even more annoying in this case since the
two values are in fact the same.
This also occurs if I declare the numWheels property as a functional property,
so that's no help.
Edward Swing
Applied Research Technologist
Vision Systems + Technology, Inc., a SAS Company
6021 University Boulevard * Suite 360 * Ellicott City * Maryland * 21043
Tel: 410.418.5555 Ext: 919 * Fax: 410.418.8580
Email: [email protected]<mailto:[email protected]>
Web: http://www.vsticorp.com<http://www.vsticorp.com/>
