Re: rdfs:class and rdfs:resource

At 4:02 AM -0700 2003-05-08, Richard H. McCullough wrote:
>The way I see it, every resource is EITHER an individual OR a class.

This is because you do not use the term "class" in the same way as 
RDF. The seeming paradox only arises when you try and make an 
instance of rdfs:Class correspond to your idea of what a "class" is.

Remember: according to the way the terms are used in RDF (and OWL), 
the set of resources belonging to a class is distinct from the class 
itself.

One can draw a parallel to Java here. Java has an Object class, which 
all objects are instances of, and a Class class, which all classes 
are instances of. Class is a subclass of Object, Object is an 
instance of Class, and Class is an instance of Object. However: 
Object is NOT a subclass of Class.

This is exactly the situation in RDFS:

TRUE:
	rdfs:Class rdfs:subClassOf rdfs:Resource .
	rdfs:Resource rdf:type rdfs:Class .
	rdfs:Class rdf:type rdf:Resource .

UNTRUE:
	rdfs:Resource rdfs:subClassOf rdfs:Class .
-- 
Dave Menendez - zednenem@psualum.com - http://www.eyrie.org/~zednenem/

Received on Thursday, 8 May 2003 15:13:19 UTC