- From: Dave Reynolds <der@hplb.hpl.hp.com>
- Date: Tue, 25 Mar 2003 11:01:20 +0000
- To: lchewhun@dso.org.sg
- CC: www-rdf-logic@w3.org
lchewhun@dso.org.sg wrote: > > I'm interested in what CANNOT be represented (declared) in OWL/DAML. Your > comments or pointers to papers are much appreciated. > > What I'm hoping to do is to be able to represent constraints (or axioms or > rules) in a DAML ontology so that an inferencing engine can check the ontology > for consistency. Ian Horrocks and Benjamin Grosof have some working papers such as [1] which compare expressivity of DAML/OWL to rule or logic programming languages. In particular, they point out that DL languages can't represent predicates involving multiple variables or involving predicate chains other than transitive closures. Thus a constraint such as "my grandfather must be older than me" would be tricky on both counts. Personally I think the semantic web will need a rich constraint expression language eventually, perhaps it could build upon something like OCL by using path expressions to identifying the values being constrained? Dave [1] http://www.cs.man.ac.uk/~horrocks/Private/DLP/DLP-v9-brief.pdf -- Hewlett-Packard Laboratories | Phone: +44-117-3128165 Filton Road, Stoke Gifford | FAX: +44-117-3128925 Bristol BS34 8QZ, UK | dave.reynolds@hpl.hp.com
Received on Tuesday, 25 March 2003 06:01:54 UTC