- From: Jerome Euzenat <Jerome.Euzenat@inrialpes.fr>
- Date: Wed, 13 Nov 2002 18:37:35 +0100
- To: "Massimo Marchiori" <massimo@w3.org>, "pat hayes" <phayes@ai.uwf.edu>, "Jeff Heflin" <heflin@cse.lehigh.edu>
- Cc: <www-webont-wg@w3.org>
Hello, In his message (RE: MT for imports (was: Re: Imports Proposal)) of 13/11/2002, Massimo Marchiori wrote: >Yes, that's precisely the major unanswered issue I was pointing out in >http://lists.w3.org/Archives/Public/www-webont-wg/2002Nov/0117.html >(and previous emails) >"owl entailment would depend on the timed web structure" >and raised as very first objection at the first telecon we had on this ;) The timed web structure applies to ontologies exactly like it applies to hyperlinks in html, xsl:include and xsl:imports in XSLT, etc. So, my opinion that: (1) we should not have to consider this, we should just consider the state of the web at that moment; (2) we should deal with it "gracefully", i.e. try to not be bothered by failures. To that extend, I would suggest that if we fetch an ontology it is added to the current one, if we cannot (404 or else) it reduces to the empty set. This should not be that disturbing as long as when there is more ontology, there is only less models and thus more consequences (summary: the more 404, the less we can deduce, but we still can). The point is that, if we constraint too much the semantics on the state of the web, we shall deduce nothing in a great number of cases. If we do not state the semantics of import (or allow to ignore it), then we might deduce too much (with regard to the designer's expectations) in a number of cases. Of course, imports are important and having a semantics for these is part of the job. But, concerning the trouble of stacking owl:import on RDF, I think this is a pity that RDF does not includes an rdf:import. If I remember well, there is a proposed xml:include somewhere as well and I would have liked to see an owl:import based on an rdf:import relying in its xml form on xml:include. -- Jérôme Euzenat __ / /\ INRIA Rhône-Alpes, _/ _ _ _ _ _ /_) | ` / ) | \ \ /_) 655, avenue de l'Europe, (___/___(_/_/ / /_(_________________ Montbonnot St Martin, / http://www.inrialpes.fr/exmo 38334 Saint-Ismier cedex, / Jerome.Euzenat@inrialpes.fr France____________________/ Jerome.Euzenat@free.fr
Received on Wednesday, 13 November 2002 12:37:28 UTC