Why Property in NS RDF and Class in RDFS?

Dear all,
I'm new to RDF and have some questions about RDF M&S and RDFS:

a.In RDFS(http://www.w3.org/TR/2002/WD-rdf-schema-20020430/)why
Property is defined in the namespace of RDF while Class in RDFS?
In my opinion,Class is the class name of nodes and Property is the class name of arcs. They seem to have the same statuses.

b.I read some RDF api proposals.Most of them define Statement,
Model,Container as subclasses of Resource. Could them be manipulated
 as Resources in RDF models? I think they are boxes containing 
Resources but not Resources.

c.In API,should Property be defined as a class (for example,
in Java, Proeprty maybe be defined as a subclass of Resource)
or an instance of Resource named as "Property"? If it is a java class,
I wonder how to understand the situation when an instance of 
 Property is put in a statement as subject or object(maybe in a
 schema,a property p is in a triple (p,subPropertyOf,ppp)).

Many thanks!

Jeff Zhang

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Received on Monday, 1 July 2002 07:31:05 UTC