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Re: on media types for OWL (5.13)

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Wed, 30 Oct 2002 21:44:15 -0500 (EST)
Message-Id: <20021030.214415.68540393.pfps@research.bell-labs.com>
To: hendler@cs.umd.edu
Cc: www-webont-wg@w3.org

From: Jim Hendler <hendler@cs.umd.edu>
Subject: Re: on media types for OWL (5.13)
Date: Wed, 30 Oct 2002 20:22:02 -0500

> At 6:09 PM -0500 10/30/02, Peter F. Patel-Schneider wrote:

[...]

> >Is an agent that is validly reading the following OWL document
> >
> >   <rdf:RDF xmlns:rdf="...the usual...">
> >    <rdf:Description rdf:about="http://foo.ex/bar#john">
> >      <rdf:type>
> >         <rdf:Description rdf:about="http://foo.ex/bar#Student">
> >      </rdf:type>
> >    </rdf:Description>
> >   </rdf:RDF>
> >
> >allowed to respond that it does *not* entail
> >
> >   <rdf:RDF xmlns:rdf="...the usual..."
> >    <rdf:list>
> >     <rdf:first rdf:resource="http://foo.ex/bar#john" />
> >     <rdf:rest rdf:resource="...the usual...#nil />
> >    </rdf:list>
> >   </rdf:RDF>
> >
> >
> >[...]
> >
> >My belief is that there needs to be several media types to keep things like
> >this straight.
> 
> 
> Peter -
>   Sorry, but this one went right over my head.  Why does the first one 
> entail the second one?  I don't understand why it entails the list 
> (john)? This makes it hard for me to figure out where the problem is 
> that needs a special Mimetype.

Because, as has been mentioned multiple times, the OWL syntax has to exist
in all interpretations, or else the entailments don't come out right, and
a list like the one above is a part of OWL syntax (namely a part of a oneOf
whose sole element is John).

>   Also, if the first one was not an OWL document (i.e. was app/RDF) 
> how would it change the point you're trying to make?

Well, the whole point is that you can't tell what kind of a document it is
just by its contents.  If you consider the first document as RDF, then the
entailment would not follow.

>   Afraid I need this is words of one syllable - this conversation has 
> gotten above my limited level of competence on mime types

Well, my understanding of MIME types is also quite limited, but I believe
that they are supposed to tell you how to interpret the bits of a
document.  My point is that there is no way to distinguish between RDF/XML and
OWL/RDF/XML documents, and the difference matters.

>   thanks
>   JH

peter
Received on Wednesday, 30 October 2002 21:44:28 GMT

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