- From: Ian Horrocks <horrocks@cs.man.ac.uk>
- Date: Fri, 6 Jul 2001 18:13:39 +0100 (BST)
- To: Dan Connolly <connolly@w3.org>
- Cc: Stephen Reed <reed@cyc.com>, www-rdf-logic@w3.org
On June 27, Dan Connolly writes: > Stephen Reed wrote: > > Doorways are subclasses of Portals and Artifacts, and the class of > > doorways is an instance of the class of types of existing objects. > > > Is it legal DAML+OIL to have both type and subClassOf statements > > describing a class? > > Yes, I believe so; e.g. daml:TransitiveProperty. It is legal in the sense that all rdf(s) is legal DAML+OIL. However, DAML+OIL does not give a semantics to this kind of usage. As far as TransitiveProperty is concerned, DAML+OIL only gives a semantics to instances of TransitiveProperty - the type and subClassOf statements relating to TransitiveProperty only have rdf(s) semantics, such as they are. Regards, Ian > > I presently fail the DAML XML validator on this point. > > That looks like a bug to me; what diagnostic do you get? > > > > > > In the Cyc ontology we allow classes to be instances of other classes > > which are meant to be types of classes. > > > > An example is: > > > > <daml:Class rdf:ID="Doorway"> > > <rdfs:label>doorways</rdfs:label> > > <rdfs:comment>A collection of portals. Each element of > > #$Doorway is a portal in some instance of > > #$ShelterConstruction, suitable for people (and perhaps > > vehicles) to enter and exit. For example, doorways to > > houses, office buildings, elevators, automobiles, airplanes, > > garages, etc.</rdfs:comment> > > <guid>bd58f914-9c29-11b1-9dad-c379636f7270</guid> > > <rdf:type rdf:resource="#ExistingObjectType"/> > > <rdfs:subClassOf rdf:resource="#Portal"/> > > <rdfs:subClassOf rdf:resource="#Artifact"/> > > </daml:Class> > > > > -- > Dan Connolly, W3C http://www.w3.org/People/Connolly/ >
Received on Friday, 6 July 2001 13:12:31 UTC