- From: Bernard Vatant <bernard.vatant@mondeca.com>
- Date: Thu, 24 Apr 2003 17:51:51 +0200
- To: <www-rdf-logic@w3.org>
- Cc: "Maria Teresa Pazienza" <pazienza@info.uniroma2.it>, "Fabio Zanzotto" <zanzotto@info.uniroma2.it>, "Patrizia Paggio" <patrizia@cst.dk>
In the framework of the ongoing European project MOSES, we want to use the university ontology: http://www.cs.umd.edu/projects/plus/DAML/onts/univ1.0.daml And linked reference ontologies: http://www.cs.umd.edu/projects/plus/DAML/onts/docmnt1.0.daml http://www.cs.umd.edu/projects/plus/DAML/onts/base1.0.daml http://www.cs.umd.edu/projects/plus/DAML/onts/general1.0.daml In the last one, you find the class "Thing" defined as a subclass of "PhysicalObject" <Class ID="Thing"> <label>thing</label> <subClassOf resource="#PhysicalObject" /> </Class> <Class ID="PhysicalObject"> <label>physical object</label> <subClassOf resource="http://www.cs.umd.edu/projects/plus/DAML/onts/base1.0.daml#SHOEEn tity" /> </Class> And at http://www.cs.umd.edu/projects/plus/DAML/onts/base1.0.daml <Class ID="SHOEEntity"> <label>SHOE Entity</label> <subClassOf resource="#Entity" /> <comment>The preferred ancestor category of all SHOE categories defined outside this ontology.</comment> </Class> <Class ID="Entity"> <label>Entity</label> <comment>The preferred ancestor category of all SHOE categories. Do not subcategorize from this category--use SHOEEntity instead.</comment> </Class> So, clearly the subclassification we get from all that is as following: Entity > SHOEEntity > PhysicalObject > Thing On the other end, Thing is defined as the "Top Class" by DAML+OIL In http://www.w3.org/TR/daml+oil-reference "Two class names are already predefined, namely the classes daml:Thing and daml:Nothing. Every object is a member of daml:Thing, and no object is a member daml:Nothing. Consequently, every class is a subclass of daml:Thing and daml:Nothing is a subclass of every class." This seems consistent with OWL http://www.w3.org/TR/2003/WD-owl-features-20030331/ "There is a built-in most general class named Thing that is the class of all individuals and a superclass of all OWL classes." So I suppose "Entity" is a subclass of daml:Thing? Or are they considered equivalent? In any case to avoid loops we have clearly to make "daml:Thing" and the PhysicalObject subclass "Thing" distinct. But the terminology is potentially confusing. Have people already noticed that as an issue? If yes, how has it been solved? Thanks for your knowledgeable feedback Bernard Vatant Senior Consultant Knowledge Engineering Mondeca - www.mondeca.com bernard.vatant@mondeca.com
Received on Thursday, 24 April 2003 11:52:03 UTC