- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Thu, 19 Jun 2003 15:31:08 +0100
- To: Sean Bechhofer <seanb@cs.man.ac.uk>
- CC: www-webont-wg@w3.org
This looks correct ....
I suggest that:
- all versions of the doc use an xml:base
- all versions of the doc use xmlns with URI refs which work with that base.
- that the xml:base should be the undated publication URL i.e.
"http://www.w3.org/TR/owl-guide/food.owl"
Jeremy
Sean Bechhofer wrote:
>
> I believe there are still some anomolies in the guide ontologies at:
>
> http://www.w3.org/2001/sw/WebOnt/guide-src/food.owl
> http://www.w3.org/2001/sw/WebOnt/guide-src/wine.owl
>
> In, for example, food.owl, there is an xml namespace declaration in the
> RDF header:
>
> xmlns="http://www.w3.org/2001/sw/WebOnt/guide-src/food#"
>
> This means that any "vanilla" elements used in this scope will be in this
> namespace, e.g.
>
> <DarkMeatFowl rdf:ID="Duck"/> [1]
>
> However according to my understanding of the rules for resolving names,
> which seems to be borne out with experimental evidence from examining the
> result of parsers, the xmlns declaration does *not* apply to attributes --
> by default they get resolved to the base URI of the document. Somebody
> *please* shout if I'm wrong here because to be honest I find this
> namespace resolution highly confusing.... Assuming that I'm right though,
> this means that the statement above is actually saying:
>
> http://www.w3.org/2001/sw/WebOnt/guide-src/food.owl#Duck
>
> rdf:type
>
> http://www.w3.org/2001/sw/WebOnt/guide-src/food#DarkMeatFowl
>
> which is not, I think, what is intended. In order to make sure that the
> attributes end up in the same namespace, you need (I think) an xml:base
> attribute, e.g:
>
> xml:base="http://www.w3.org/2001/sw/WebOnt/guide-src/food"
>
> As they currently stand, I believe the example ontologies are *not* DL due
> to this mismatch, as a number of things are not explicity typed. For
> example, there is a statement:
>
> <owl:Class rdf:ID="DarkMeatFowl"/>
>
> This then refers to a uri
>
> http://www.w3.org/2001/sw/WebOnt/guide-src/food.owl#DarkMeatFowl
>
> which is not the same "DarkMeatFowl" used in the earlier rdf:type
> assertion, and this means that [1] is using an "untyped" class.
>
> I think the /TR/owl-guide ontologies have the same problem.
>
> It might be worth a note in one of the documents about this kind of thing
> -- as I said above, it gives me a headache and I'm sure I'm not the only
> one.....
>
> Cheers,
>
> Sean
>
>
Received on Thursday, 19 June 2003 10:33:28 UTC