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Re: declaredAs

From: Matthew Horridge <matthew.horridge@cs.man.ac.uk>
Date: Wed, 25 Jul 2007 15:13:33 +0100
Message-Id: <D1C1028E-5318-4406-8C4E-E50C0F08F395@cs.man.ac.uk>
To: Owl Dev <public-owl-dev@w3.org>

Revisiting the issue of declaring and typing, because it is causing  
problems - in particular backwards compatibility with OWL 1.0

Below is a message to the list from Evren Sirin

> On 26 Jan 2007, at 20:22, Evren Sirin wrote:
>
> In OWL 1.0, there is not really a difference between declarations  
> and typing. Having a triple <p, rdf:type, owl:ObjectProperty>   
> constitutes its declaration (as on object property in this case). I  
> agree that requiring declaration for every resource is not a good  
> idea. OWL-DL requires every resource to be typed and it turns out  
> that many ontologies out on the Web fall into OWL-DL expressivity  
> but do not meet this requirement. But now are we separating  
> declarations from typing and say that declarations are not required  
> but typing still is?
>
>
> And if I understand the mapping from RDF graphs to OWL 1.1  
> correctly, an ontology that has just the above triple (or any any  
> number of rdf:type triples where the object is one of  
> owl:ObjectProperty, owl:DatatypeProperty, or owl:Class) will be  
> mapped to an empty OWL 1.1 ontology. I don't think this is a  
> desired result.

I am in complete agreement with the last point.  There are plenty  
(enough to cause problems) of ontologies that just consist of  
rdf:type triples such as A rdf:type owl:Class.  As Evren points out,  
when parsed, these documents result in empty ontologies, which is  
less than desirable - users of tools such as editors find this  
confusing and don't expect it.  Does anyone have any suggestions  
about how to resolve this?

Cheers,

Matthew
Received on Wednesday, 25 July 2007 14:15:02 UTC

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