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Re: Declarative limitations of OWL/DAML

From: Dave Reynolds <der@hplb.hpl.hp.com>
Date: Tue, 25 Mar 2003 17:17:36 +0000
Message-ID: <3E808F30.88473A51@hplb.hpl.hp.com>
To: Ian Horrocks <horrocks@cs.man.ac.uk>
CC: lchewhun@dso.org.sg, www-rdf-logic@w3.org

Ian Horrocks wrote:
> A couple of points. DLs certainly CAN represent predicates involving
> multiple variables and predicate chains, it just happens that the
> particular DL on which DAML/OWL are based does not include these
> features 

Apologies for my imprecise language - I should indeed have said "the DLs behind

> (there are a variety of reasons for this, not the least of
> which is the fact that the RDF and XML type systems do not specify
> n-ary predicates). 

I assume there are also complexity arguments. Predicate chains would be
compatible with the RDF substrate but I assumed that the combination of role
composition with the other operators in OWL would have pushed up the
computational complexity further. Is that correct?

> See [2,3] for details about DL support for datatypes
> (called concrete domains in DLs).

Thanks for the references.

Received on Tuesday, 25 March 2003 12:18:18 UTC

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