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Re: Comments

From: Smith, Michael K <michael.smith@eds.com>
Date: Tue, 6 Jan 2004 13:44:13 -0600
Message-ID: <2928D6FE55D5584390909578CAC8397D0665D14E@usplm216.txpln.us.eds.com>
To: public-webont-comments@w3.org
Cc: pgaspart@ulb.ac.be

Dear Prof. Gaspart,

Thanks for your comments concerning the use of xml:base in 
the OWL Guide.

The Working Group has discussed these comments by e-mail [1].
It was agreed that it is a bit weird that xml:base may be a
URI reference rather than simply a URI.

This use is based on an effort to provide a style of ontology
definition designed to reduce errors, given the interactions between
entity declarations and namespaces.  And the cleanest set of
declarations we were able to arrive at are:

 Entity decl   : <!ENTITY vin "http://www.example.org/wine#
<http://www.example.org/wine#> " >
 Namespace decl: xmlns:vin = "&vin;"
 Base decl     : xml:base = "&vin;"

We struggled to get to this point.  As explained below, while not 
elegant, the examples you highlight are not errors.  Therefore 
we intend to leave them as they are.

(The following detail is thanks to Jeremy Carroll.)

The use of xml:base in OWL is specified by RDF/XML Syntax (Revised) [2].
See section 5.3 in 

http://www.w3.org/TR/2003/PR-rdf-syntax-grammar-20031215/#section-baseURIs
<http://www.w3.org/TR/2003/PR-rdf-syntax-grammar-20031215/#section-baseURIs>


specifically the words "any fragment part is ignored."

These words are further clarified in the test xmlbase/test013 in the RDF 
Test Cases [3].

The URL for the RDF/XML file in that test case is:

http://www.w3.org/2000/10/rdf-tests/rdfcore/xmlbase/test013.rdf
<http://www.w3.org/2000/10/rdf-tests/rdfcore/xmlbase/test013.rdf> 

This shows an xml:base of "http://example.org/dir/file#frag
<http://example.org/dir/file#frag> ",  two same 
document references rdf:about="" and rdf:ID="foo" and a relative URI 
rdf:resource="relpath". All three are resolved as if the xml:base were 
"http://example.org/dir/file <http://example.org/dir/file> ". (This can be
seen by examination of the 
corresponding ntriple file test013.nt).

Please reply, with a cc to public-webont-comments@w3.org, indicating 
whether you are satisfied with this response.

If you wish to follow up with comments on section 5.3 of RDF/XML Syntax or 
the RDF Test Cases, then such comments should be directed to 
www-rdf-comments@w3.org

Thanks again,
On behalf of Web Ontology WG,

Mike

Michael K. Smith  PhD, PE
EDS - Austin Innovation Centre
98 San Jacinto
Austin, TX 78701
 
Phone:+1-512-404-6683
mailto:michael.smith@eds.com <mailto:michael.smith@eds.com> 


[1]
http://lists.w3.org/Archives/Public/www-webont-wg/2004Jan/thread.html#4
<http://lists.w3.org/Archives/Public/www-webont-wg/2004Jan/thread.html#4> 

[2]Beckett, RDF/XML Syntax Specification (Revised)
http://www.w3.org/TR/2003/PR-rdf-syntax-grammar-20031215/
<http://www.w3.org/TR/2003/PR-rdf-syntax-grammar-20031215/> 

[3]Grant and Beckett, RDF Test Cases
http://www.w3.org/TR/2003/PR-rdf-testcases-20031215/
<http://www.w3.org/TR/2003/PR-rdf-testcases-20031215/> 









Michael K. Smith  PhD, PE
EDS - Austin Innovation Centre
98 San Jacinto
Austin, TX 78701
 
Phone:+1-512-404-6683
mailto:michael.smith@eds.com <mailto:michael.smith@eds.com> 
Received on Tuesday, 6 January 2004 14:46:26 GMT

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