- From: Smith, Michael K <michael.smith@eds.com>
- Date: Tue, 6 Jan 2004 13:44:13 -0600
- 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 UTC