- From: Jeff Z. Pan <pan@cs.man.ac.uk>
- Date: Thu, 6 Mar 2003 10:18:56 -0000
- To: "Bob MacGregor" <macgregor@ISI.EDU>
- Cc: <www-rdf-logic@w3.org>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
From: "Bob MacGregor" <macgregor@ISI.EDU> Subject: Re: Why isn't FunctionalProperty a subClassOf owl:ObjectProperty? > >Well, neither of these make much sense in OWL DL, domains and ranges of OWL > >DL datatype properties are disjoint of necessity. [...] > Are you claiming that > > :greaterThan :domain :Integer. > :greaterThan :range :Integer. > > are illegal triples? If not, then why are my first three triples not > allowable? Yes, they are illegal - since Integer is not disjoint with itself. Again, I think you confuse datatype properties with datatype predicates. Datatype properties relate individual objects with data values, and datatype predicates are constraints imposed on the values of datatype properties. OWL support datatype properties. It makes use of datatypes and datatype predicates defined in XML Schema. In your example, greaterThan is a binary datatype predicates. Currently XML Schema Part 2 supports doesn't support binary datatypes predicates, so OWL doesn't support them in its datatype constructs. If some type systems support binary (or generally speaking, n-ary) datatype predicates, OWL can be easily extended to support them in its datatype constructs. E.g. we can define a AllValueFrom restriction like this (assuming income and expense are functional datatype properties): AllValueFrom income,expense.greaterThan it says the value of income should be greater than that of expense. This above form of restriction is expressible in the SHOQ(Dn) DL [1], which has been proven to be decidable if the set of datatypes and datatype predicates used is conforming. In the above example, if we consider the set of datatype and datatype predicates as {real, not real, greaterThan, lessThanOrEqual}, then it is conforming. Hope it helps. Regards, Jeff -- Jeff Z. Pan ( http://DL-Web.man.ac.uk/ ) Computer Science Dept., The University of Manchester [1] http://www.cs.man.ac.uk/~panz/Zhilin/download/Paper/Pan-Horrocks-datatype-2002.pd f > > Bob > > > > Robert MacGregor > Project Leader > USC Information Sciences Institute > 4676 Admiralty Way, Marina del Rey, CA 90292 > macgregor@isi.edu > Phone: 310/448-8423, Fax: 310/822-6592 > Mobile: 310/251-8488 > >
Received on Thursday, 6 March 2003 05:16:13 UTC