- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Wed, 08 Oct 2003 09:52:05 +0100
- To: Ian Horrocks <horrocks@cs.man.ac.uk>
- Cc: Dan Connolly <connolly@w3.org>, Jim Hendler <hendler@cs.umd.edu>, www-webont-wg@w3.org
Jeremy: >>I am not sure what Martin's current position is - merely that without a >>single implementation passing these two tests that the response given >>during LC is invalidated. >> Ian: > Surely you can't be serious! It has always been crystal clear > (including in our responses to LC comments) that we don't currently > have a decision procedure for OWL DL (we removed the definition of > "complete OWL Lite consistency checker" from test for this reason). > The inability of existing implementations to reliably prove the > consistency of OWL DL ontologies is an obvious consequence of this > fact. Moreover, the spec allows conforming consistency checkers to > return "Unknown" when they are unable to determine if a document is > consistent or inconsistent. > Of course you are right that there was much in the response that remains pertinent, and requesting reopening discussion is not intended as a free-for-all. However text such as [[ The WG has been made aware of implementations of OWL DL that include both inverseOf and oneOf and which seem to be performing well in practice. The working group will definitely consider their status and usability before deciding on our schedule with respect to Candidate Recommendation and Proposed Recommendation. ]] suggests that straightforward examples including both features should be tractable. The decisions made about what was in DL were known to be pushing the boundaries, and the changes we made during LC reflect that we were not expecting implementations to be able to pass maybe some of the more difficult DL tests (e.g. 3-sat encoded with oneof). The guide examples, in contrast, are not attempting to be clever or to be a challenge to systems, merely exemplory use of DL. As far as I can tell, most of my colleagues see the current failure to prove these tests as justifying our earlier scepticism about the usefulness of the DL boundary, but accept that given where we are in the process, the likely outcome will be adequate text in the guide exlaining how to remain within a smaller more tractable subset. Jeremy
Received on Wednesday, 8 October 2003 05:00:49 UTC