Re: semantics status of RDF(S)

> 1/ There are many places in the RDF and RDFS documents where vitally
> important statements about the semantics of RDF or RDFS are presented with
> no formal backup, and in a totally inadequate fashion. 
> 
> For example, in Section 2.3.2 of the RDFS Specification 1.0 there are two
> paragraphs that give conditions on rdfs:subClassOf.  As far as I can tell,
> this is the only place that attempts to provide a meaning for rdfs:subClassOf.
> However, these two paragraphs use terms that are not defined in RDF or RDFS
> (such as set - classes are not sets and thus the subset relationship is not
> meaningful on classes), are sloppy in their terminology (rfds:subClass
> vs. sub/superset vs. subclass), and make unenforceable pronouncements
> (there is nothing in RDF(S) to prevent someone from creating the triple
> {rdfs:subClassOf, foo, foo}).

I am puzzled at this criticism of RDF(S).  It is not news that the RDF
and RDFS specs do not contain an adequate formalization and semantics. 
However, as you know, as least one formalization of the semantics or RDF
and RDFS has been produced and is presented in the paper by Deborah
McGuinness and myself titled "An Axiomatic Semantics for RDF, RDF
Schema, and DAML+OIL"
(http://www.ksl.Stanford.EDU/people/dlm/daml-semantics/abstract-axiomatic-semantics.html). 
There no doubt have been others.  Criticism of existing formalizations
of RDF and RDFS would seem more appropriate and productive rather than
simply criticizing the specs.

Richard

Received on Monday, 2 April 2001 01:46:17 UTC