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RE: [Q] how to reference a rdf schema in an rdf instance file ?

From: Danny Ayers <danny666@virgilio.it>
Date: Tue, 3 Jun 2003 13:44:43 +0200
To: <hgadm@cswebmail.com>, <www-rdf-interest@w3.org>
Message-ID: <BKELLDAGKABIOCHDFDBPAEEBCPAA.danny666@virgilio.it>


> how do I reference a rdf schema that defines a certain
> rdf instance file within that instance file ?
>
> Do I use something like:
> <rdf:Description
> rdf:about=http://expm.rd.ambl.net/kno/transporters01.rdf>;
> <rdfs:isDefinedBy
> rdf:resource=http://expm.rd.ambl.net/kno.rdfs>;

According to the spec [1] :

S rdfs:isDefinedBy O
states that the resource O defines S. It may be possible to retrieve
representations of O from the Web, but this is not required. When such
representations may be retrieved, no constraints are placed on the format of
those representations.

So if you want to do anything with the schema, you'll have to do this at the
application level.

> BTW, does rdf provide for the inclusion of XML schema
> files
> or do I need DTDs ?

Inclusion in what sense? Remember that RDF isn't XML, just RDF/XML is just
one serialization of the model, so the constructs of XML schema aren't
necessarily appropriate. RDF can use values given as XML schema datatypes
[2], but XML schema validation on RDF documents doesn't really work because
the RDF semantics work on a different level. DTDs are a non-starter because
of the alternate representations (full, abbreviated, a mix) possible for the
XML representation.

Cheers,
Danny.

[1] http://www.w3.org/TR/rdf-schema/#ch_isdefinedby
[2] http://www.w3.org/TR/rdf-concepts/#section-use-xsd
Received on Tuesday, 3 June 2003 07:47:46 GMT

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