Joint Committee Minutes 2 October 2001

This page summarizes the telecon for the Joint US/EU Committee on Agent Markup Languages held from 1300 to 1400 PDT on 2 October 2001. These minutes were prepared by the chairman, and were approved during the 9 October telecon.



Pat Hayes announced that the RDF Core WG has decided not to prohibit rdfs:subPropertyOf cycles.

Last Week's Minutes

The minutes from September 25 were approved by those present.

DAML+OIL Submission

Peter will shortly submit a new version of the axiomatization with formatting changes. There are no substantive differences.

Model Theory

Pat introduced the RDF(S) Model Theory he has been developing for the RDF Core WG. This was recently published as a Working Draft. Peter found some bugs and there is significant on-going discussion on w3c-rdfcore-wg.

Peter has updated the DAML+OIL model theory to address Pat's RDF(S) theory. The current theory covers only the DAML+OIL extensions to RDF(S). The most significant change is the addition of explicit extension mapping, a trick Pat learned from Chris Menzel and used in the RDF(S) Model Theory which is very applicable DAML+OIL and offers the potential for an encompassing theory. Peter has distributed first and second versions of this update; a third version is in-progress.

The updated model theory will look more like the KIF axiomatic semantics. Pat has a contractual obligation to map between the model theoretic and axiomatic semantics, but is waiting for the dust to settle.

There's considerable on-going discussion regarding literals. Pat would like to make model theory agnostic with respect to literals, syntax, etc., minimizing the set of issues on which it has to express an opinion.

Harold asked about the relationship between the Model Theory and XML Schema data types. There's also considerable on-going-discussion on this topic, which the Model Theory tries to avoid. ACTION (Mike): survey current usage of datatypes in DAML+OIL.

rdfs:label and rdfs:comment in DAML+OIL

Peter's updated model theory addresses every statement in daml+oil.daml except for the uses of rdfs:label and rdfs:comment. Explicitly addressing these would add 50-100 lines (an extra 1/3) to the Model Theory.

ACTION (everyone): review the current comments. Some may be obsolete.

RESOLVED: don't change the current file (which is part of the submission, etc.). Note the exclusion in the Model Theory.

RDF Core/Joint Committee/Web Ont Coordination

Peter expressed some concern about coordination among groups working on different layers of the Semantic Web.


Pat asked about the status of our rules proposal and coordination among various rules groups (particularly us and the new www-rdf-rules email list).

ACTION (Mike): ping Benjamin and Ian regarding their next iteration of the rules proposal

Next Week

We'll expect a report on the EU/NSF meeting, and continue our query discussions.

Pat and Peter volunteered to provide an update on the Model Theory, which should be more stable by then.


Kelly Barber's raw notes
last week's minutes
Joint Committee home page

$Id: 2001-10-02.html,v 1.4 2001/10/13 03:52:19 mdean Exp $