W3C home > Mailing lists > Public > www-rdf-logic@w3.org > June 2001

Re: Can DAML class also be an instance?

From: Dan Connolly <connolly@w3.org>
Date: Wed, 27 Jun 2001 10:55:45 -0500
Message-ID: <3B3A0201.EFED1867@w3.org>
To: Stephen Reed <reed@cyc.com>
CC: www-rdf-logic@w3.org
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.

> 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 Wednesday, 27 June 2001 11:55:48 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 2 March 2016 11:10:35 UTC