Re: ACTION-178: What is ISSUE-116 (Axiomatic Triples for OWL R) about?

From: Ivan Herman <ivan@w3.org>
Subject: Re: ACTION-178: What is ISSUE-116 (Axiomatic Triples for OWL R) about?
Date: Tue, 12 Aug 2008 16:37:55 +0200

> 
> 
> Ian Horrocks wrote:
> > Michael (and Ivan),
> > I don't have any problem with axiomatic triples in principle. However,
> > while they may be (relatively) harmless in principle, I worry that they
> > could be extremely damaging from an implementation perspective.
> > Presumably, making axiomatic triples be part of OWL RL (Full) would
> > mean extending the rule set so that it would generate such
> > triples. There could be a very large (perhaps even infinite) number of
> > such triples. This might be a serious burden on implementations and lead
> > to a significant degradation in performance.
> > I CCed Zhe on this in the hope that we can get a view on this from an
> > OWL R implementer.
> > 
> 
> Although not Zhe:-) but I did implement RDFS a while ago using Herman
> ter Horst's approach. What it does is for a specific graph was to look
> at the rdf:_i properties, looks at the maximum 'i', and use the axioms
> (eg, rdf:_1 rdf:type rdfs:ContainerMembershipProperty) for that interval
> only. That takes care of the infinite issue for each specific graph.

Does it?  It seems to me that this method will not notice that

rdf:_1 rdf:type rdfs:ContainerMembershipProperty .

RDFS-follows from the empty graph.

> Yes, performance might be an issue, Zhe is better positioned to answer
> that.
> 
> Ivan

peter

Received on Tuesday, 12 August 2008 14:59:28 UTC