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Re: xml:base in OWL-S files

From: David Martin <martin@AI.SRI.COM>
Date: Thu, 14 Oct 2004 17:45:14 -0700
Message-ID: <416F1D9A.9090109@ai.sri.com>
To: Daniel Elenius <daele@ida.liu.se>
CC: public-sws-ig@w3.org

I agree with you, Daniel.  It seems intuitive to me that the "URI of the 
document containing the ontology" would not include the "#".  Also, 
here's an example that conforms to your idea:


(This is OWL code for SWRL:

If you don't get sufficient feedback on this list, www-rdf-logic would 
probably be a better place to post this particular question.



Daniel Elenius wrote:

> Working with the OWL-S files, and struggling with imports in protege, I 
> have looked at some details of the OWL-S files, in, well some detail :)
> And I want to discuss the following issue.
> All the OWL-S files now have an xml:base defined, such as
> xml:base="&process;"
> in Process.owl, where &process; is defined by <!ENTITY process 
> "http://www.daml.org/services/owl-s/1.1/Process.owl">
> But ordinary namespace prefixes have a hash (#) in the end, such as:
> xmlns:grounding= "&grounding;#"
> where we have <!ENTITY grounding 
> "http://www.daml.org/services/owl-s/1.1/Grounding.owl">
> Now, the question is, should xml:base URIs have the # in the end? In the 
> examples in the OWL Web Ontology Language Guide 
> (http://www.w3.org/TR/2004/REC-owl-guide-20040210/), they do. For example:
> xml:base  ="http://www.w3.org/TR/2004/REC-owl-guide-20040210/wine#"
> Are these examples wrong? A lot of things suggest that they are.
> First, in the OWL Web Ontology Language Reference 
> (http://www.w3.org/TR/owl-ref/),
> Appendix A, the owl ontology itself has:
> xml:base  ="http://www.w3.org/2002/07/owl"
> (no # in the end).
> The OWL Ref says that
> "The line
>  <owl:Ontology rdf:about="">
> states that this block describes the current ontology. More precisely, 
> it states the current base URI identifies an instance of the class 
> |owl:Ontology|. It is recommended that the base URI be defined using an 
> |xml:base| attribute in the |<rdf:RDF>| element at the beginning of the 
> document."
> and the OWL Guide that
> "The rdf:about attribute provides a name or reference for the ontology.
> Where the value of the attribute is "", the standard case, the name of 
> the ontology is the base URI of the owl:Ontology element.  Typically, 
> this is the URI of the document containing the ontology.
> An exception to this is a context that makes use of xml:base which may 
> set the base URI for an element to something other than the
> URI of the current document."
> I guess this still doesn't give conclusive evidence for either variant. 
> But if we consider that
> "Syntactically, |owl:imports| is a property with the class 
> |owl:Ontology| as its domain and range" (OWL Ref) *and* that the URI 
> given to owl:imports is written _without_ the # (at least I have never 
> seen it _with_ a #), *and*
> that the xml:base gives the URI to the owl:Ontology instance, then it 
> looks like the xml:base should be
> written _without_ the #. Thus, the examples in the OWL Guide would be 
> wrong.
> What do you think?
> /Daniel
Received on Friday, 15 October 2004 00:45:31 UTC

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