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DAML+OIL bug (namespace vs baseuri)

From: Sean Bechhofer <seanb@cs.man.ac.uk>
Date: Thu, 21 Jun 2001 12:41:40 +0100 (BST)
To: www-rdf-logic@w3.org
Message-ID: <15153.56616.427432.723884@bagel>

I think there may be an error in the the DAML+OIL example at
http://www.daml.org/2001/03/daml+oil-ex.daml. It contains the
following namespace definitions:

<rdf:RDF
  xmlns:rdf ="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
  xmlns:daml="http://www.daml.org/2001/03/daml+oil#"
  xmlns:xsd ="http://www.w3.org/2000/10/XMLSchema#"
  xmlns:dex ="http://www.daml.org/2001/03/daml+oil-ex#"
  xmlns:exd ="http://www.daml.org/2001/03/daml+oil-ex-dt#"
  xmlns     ="http://www.daml.org/2001/03/daml+oil-ex#"
>

Later on, we get:

<daml:Class rdf:ID="Height">
  <daml:oneOf rdf:parseType="daml:collection">
    <Height rdf:ID="short"/>
    <Height rdf:ID="medium"/>
    <Height rdf:ID="tall"/>
  </daml:oneOf>
</daml:Class>

Now my guess is that the intention here is that this is defining a
class Height that consists of the three things short, medium and tall,
each of which are instances of Height. However, it doesn't quite do
this. The first occurrence of Height (as an rdf:ID attribute value)
resolves to <baseuri>#Height, which is actually:

http://www.daml.org/2001/03/daml+oil-ex.daml#Height

whereas the other occurrences of Height (as an element) are resolved to:
	
http://www.daml.org/2001/03/daml+oil-ex#Height

due to the use of the default namespace. Is this just a typo (i.e. the
default ns should really be ....daml+oil-x.daml#) or is there
something more going on here? I guess that using xml-base (or some
similar mechanism) might help to alleviate these problems as the
baseuri of the resources within the description would then be
explicit.

Cheers,

	Sean

==========================================================================
| Sean Bechhofer               |                                         |
| Research Fellow              |                                         |
| Information Management Group |                                         |
| Computer Science Department  |                                         |
| The University of Manchester | email: seanb@cs.man.ac.uk               |
| Oxford Road                  | Tel: +44-161-275-6145                   |
| Manchester M13 9PL           | Fax: +44-161-275-6236                   |
|------------------------------------------------------------------------|
| WWW: http://www.cs.man.ac.uk/~seanb                                    |
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Received on Thursday, 21 June 2001 07:41:44 GMT

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