semantics for SWOL : initial message

		The Problem with Semantics in DAML+OIL


Well actually this is not a problem with DAML+OIL itself, but is instead a
conflict between the way that RDF works and the way that more-expressive
logics have to work.

The Basic Problem:

The problem is, basically, that expressive logics cannot have their syntax
show up their model theory.  Attempting to put the syntax of an expressive
logic into its model theory ends up with semantic paradoxes.  An attachment
to this message gives a detailed example of the problem.

The Proposed Solution:

What can be done?  The semantics of the Semantic Web Ontology Language
(SWOL) should be as compatible as possible with the semantics of the
Resource Description Framework (RDF).  It is possible to achieve upward
compatability by keeping the RDF syntax in the SWOL model theory, but not
putting the more-expressive part of the SWOL syntax in the SWOL model
theory.  A draft of the details of the solution are given in an attachment
to this message.

Action Items for the Clean-Up Task Force:

[Relevant comments from other WG members are welcome.]

1/ Review the attachments.

2/ Determine if you disagree with the following:
   - There is indeed a problem here.
   - The proposed solution does indeed solve the problem.
   - The proposed solution does not introduce other problems.

3 (optional)/ Make suggestions for improvements.

Schedule:

20 December 2001 teleconference: discussion of the proposal
??: draft document for face-to-face discussion
7 January 2002: final document for face-to-face discussion