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Re: comments on RDF mapping

From: Ian Horrocks <Ian.Horrocks@comlab.ox.ac.uk>
Date: Tue, 23 Oct 2007 11:49:40 +0100
Message-Id: <ECF3A090-7CF1-4FAB-979A-711BAC69C70A@comlab.ox.ac.uk>
Cc: public-owl-wg@w3.org
To: Jeremy Carroll <jjc@hpl.hp.com>

The motivation for properties such as subObjectPropertyOf is not  
related to punning. The idea is to facilitate parsing/species  
validation by enforcing strong typing. For example, it is illegal in  
OWL DL for a datatype property to be a subProperty of an object  
property, but when parsing a <P subPropertyOf S> triple, the types of  
P and S may not be known. As a result, not only will a decision on  
the species of the ontology need to be postponed, but it becomes  
dependent on a (relatively) complex and non-local condition, i.e.,  
that P and S are either both datatype properties or both object  
properties.

Ian


On 23 Oct 2007, at 11:22, Jeremy Carroll wrote:

>
>
> I think Jim's example about subObjectPropertyOf is compelling.
>
> In essence, I don't think we can publish a meaningful and helpful  
> RDF Mapping document until we have decided whether or not we accept  
> the 'punning' design in the member submission.
>
> I think this is one of the features of OWL 1.1 that causes the  
> greatest unease with the HP developers. As I understand the design,  
> language terms like subObjectPropertyOf are largely motivated by  
> the punning design.
>
> A further possible motivation is that in OWL 1.0, at I think mainly  
> my request, one design choice is that the triples version of OWL DL  
> is strongly typed, in the sense that (nearly) every URI and blank  
> node is required to have an rdf:type triple. Many of the required  
> type declarations are unnecessary, and it may be a better design to  
> allow unnecessary ones to be omitted. However, I think that the  
> explosion of terms in the member of submission is unfortuante, and  
> should be avoided.
>
> Jeremy
>
>
>
>
Received on Tuesday, 23 October 2007 10:49:49 GMT

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