- From: Jeremy Carroll <jjc@hpl.hp.com>
- Date: Sat, 1 Feb 2003 21:09:11 +0100
- To: www-webont-wg@w3.org
>> ... I have already proposed a small inelegant fix [1], which you have sneered >> at. I would value having my proposal demolished. >I don't see a solution there. For example, how does this allow for >annotations on classes or properties in the direct semantics? It does not, and does not need to. The annotations on classes or properties are ignored in the direct semantics. Our job does not concern the abstract syntax and semantics, but the exchange syntax and its semantics. It is a convenient tool to use the abstract syntax and its semantics because the abstract syntax conforms better with the syntax the DL community uses, and the direct semantics borrows from work that has been done in that field. It seems clear that that work does not cover annotations well. Annotations are the bread and butter of RDF, and so it should be no surprise that the semantics of RDFS works fine on annotations. The current position in AS&S is that OWL documents within the OWL DL subset are given their semantics using the direct semantics on the abstract syntax form; and this does not work for annotations. The meaning of documents can be seen in terms of interpretations, and in this sense OWL Full shows how to give a meaning to an OWL DL ontology with its annotations. An alternative view, would be to see the meaning solely in terms of consistency and entailment. With appropriate syntactic constraints, OWL DL annotations cannot cause inconsistency; so the direct semantics is fine for the definition of consistency. This alternative view is seen in the correspondence theorem. My paragraph shows how to combine the entailment of the direct semantics with the entailment of RDFS (for annotations only). >> Also, the correspondence proof needs to be overhauled. (see [2]), so that is >> no new work. > >The flaws in the proof have already been fixed. But the flaws in the theorem (not covering annotations and imports) [2] seem fundamental! Jeremy [1] section headed: "OWL Lite/DL Entailment" in http://lists.w3.org/Archives/Public/www-webont-wg/2003Jan/0523.html [2] Herman's AS & S Review: Appendix A.1: http://lists.w3.org/Archives/Public/www-webont-wg/2003Jan/0424.html
Received on Saturday, 1 February 2003 15:08:17 UTC