- From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
- Date: Wed, 28 Jan 2009 15:58:38 +0000
- To: Bijan Parsia <bparsia@cs.man.ac.uk>
- Cc: "Michael Schneider" <schneid@fzi.de>, "Sandro Hawke" <sandro@w3.org>, <public-owl-wg@w3.org>
The semantics of OWL 1 says that values of unsupported datatypes are interpreted as some element of a set that is at least as large as the union of the interpretations of all the known datatypes and is disjoint from the abstract domain. A reasoner implementing Vanilla OWL would therefore not find this entailment, but nor would it conclude that the two values are necessarily different. Ian On 21 Jan 2009, at 16:51, Bijan Parsia wrote: > > On 21 Jan 2009, at 16:42, Michael Schneider wrote: > [snip] >> I am not sure about the situation in OWL 1. Both datatypes, >> xsd:decimal and >> xsd:double, were not required to be supported, AFAIU. I would >> guess that >> there is some chance that at least /some/ existing OWL 1 DL >> reasoners will >> draw the first conclusion, > > Yes, but, arguably, erroneously as they types are disjoint in XML > Schema. > >> since the two datatypes are pretty common. But I >> believe that this would then be a proprietary extension w.r.t. the >> OWL 1 >> spec (though this extension would not be in conflict with OWL 1 DL). > > They are permitted in OWL 1, so it's unclear that one should > consider it proprietary. Varying from Schema might be considered such. > >> Anyone having better information? (E.g., did old versions of >> Pellet draw the >> first conclusion?) > > No, due to disjointness. > > Cheers, > Bijan. > >
Received on Wednesday, 28 January 2009 15:59:35 UTC