- From: Deborah McGuinness <dlm@ksl.stanford.edu>
- Date: Mon, 02 Apr 2001 09:27:04 -0700
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- CC: fikes@ksl.stanford.edu, www-rdf-logic@w3.org
- Message-ID: <3AC8A858.5A4624D7@ksl.stanford.edu>
I can not speak for the formal W3C RDF(S) committee but will relay the gist of a few personal communications. When Richard Fikes and I published our axiomatic semantics (http://www.ksl.Stanford.EDU/people/dlm/daml-semantics/abstract-axiomatic-semantics.html), we received interest from RDF(S) authors in using our axioms as the basis for the RDF(S) semantics. It is the case as far as I know that no formal statement has been made stating that our axiomatization (or any other axiomatization) is the officially blessed foundation for RDF(S). Richard and I are happy to submit our axiomatization as the starting point. We also welcome constructive suggestions on the axiomatization in its evolution in serving the DAML and broader W3C communities. I would like to support Richard's suggestion that we might focus our discussion of the need for a firm semantic foundation for RDF(S) in the form of constructive criticism of existing foundations such as our document. Deborah McGuinness "Peter F. Patel-Schneider" wrote: > The axiomatization for RDF and RDF(S) is one avenue that could be used to > provide a firm semantic foundation for RDF and RDF(S). However, this > axiomatization has (as yet) no status with respect to RDF and RDF(S). > Therefore I feel completely justified in critisizing RDF and RDF(S) as > lacking in semantic grounding. > > One desirable effect of criticism of RDF and RDF(S) as lacking in semantic > grounding should be the adoption of formal semantics for RDF and RDF(S). > RDF and RDF(S) currently exist without formal semantics. Further, there is > no indication in any official RDF or RDF(S) documents that the lack of a > formal semantics was considered to be a problem when RDF and RDF(S) were > developed. I take this to mean that some people are satisfied with the > current state of affairs. If no one complains about the lack of a formal > semantics then nothing will be done. > > It is at least a bit hopeful that there are some issues in the RDF Issue > Tracking document having to do with the lack of a formal semantics for RDF > and RDF(S). > > Peter > > From: Richard Fikes <fikes@KSL.Stanford.EDU> > Subject: Re: semantics status of RDF(S) > Date: Sun, 01 Apr 2001 20:43:11 -0700 > > > > 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 > > -- ======================= Deborah L. McGuinness Associate Director and Senior Research Scientist Knowledge Systems Laboratory Stanford University Stanford, CA 94305 dlm@ksl.stanford.edu voice 650 723 9770 fax 650 725 5850
Received on Monday, 2 April 2001 12:27:13 UTC