- From: Guus Schreiber <schreiber@cs.vu.nl>
- Date: Wed, 23 Apr 2003 11:08:22 +0100
- To: Jeff Heflin <heflin@cse.lehigh.edu>
- CC: webont <www-webont-wg@w3.org>
Jeff Heflin wrote: [..] > 3) I think the factor that makes QCRs most confusing in OWL is the > difficulty in expressing them cleanly in triples. Currently, the > Restriction class is a place to hang each restriction that is applicable > to a property. Currently, each of these is a binary predicate so the > following is perfectly fine. > > <owl:Restriction> > <owl:onProperty rdf:resource="⪚hasDigit"/> > <owl:cardinality rdf:datatype="&xsd;int">5</owl:cardinality> > <owl:allValuesFrom rdf:resource="⪚Digit" /> > <owl:someValuesFrom rdf:resource="⪚Finger" /> > </owl:Restriction> > This is not "perfectly fine". OWL currently allows only one single value or cardinality constraint witrhin a restriction class (se the relevant sections in S&AS and Ref). I agree that allowing QCRs would probably mean we have to intriduce restriction classes with two constraints on a property, but they can, in principle, be semantically distinguished from the single-statement constraints. Guus [..] -- NOTE: new affiliation per April 1, 2003 Free University Amsterdam, Computer Science De Boelelaan 1081a, 1081 HV Amsterdam, The Netherlands Tel: +31 20 444 7739/7718 E-mail: schreiber@cs.vu.nl Home page: http://www.cs.vu.nl/~guus/ [under construction]
Received on Wednesday, 23 April 2003 06:08:27 UTC