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SPARQL rdf:type predeclared?

From: Graham Klyne <GK@ninebynine.org>
Date: Wed, 13 Sep 2006 15:55:33 +0100
Message-ID: <45081BE5.2030905@ninebynine.org>
To: public-rdf-dawg-comments@w3.org

Some clarification may help...

With reference to:

[[
2.8.4 rdf:type

The keyword "a" can be used as a predicate in a triple pattern and is an
alternative for the IRI rdf:type which is
http://www.w3.org/1999/02/22-rdf-syntax-ns#type.
]]
-- http://www.w3.org/TR/rdf-sparql-query/#abbrevRdfType

and the example in the same section:
[[
  ?x    rdf:type  :Class1 .
  _:b0  rdf:type  :appClass .
  _:b0  :p        "v" .
]]

It's not entirely obvious whether the name rdf:type is predeclared, or if this
is used must the query also define the rdf: prefix?  On balance, I think
rdf:type cannot be used without first defining the rdf: prefix -- could this be
made clearer?

(BTW, I think Jena/ARQ may accept rdf:type without a prefix declaration, but
don't have firm evidence of this.)

Also, I would assume that the keyword "a" can be used without declaring the rdf:
prefix.

#g

-- 
Graham Klyne
For email:
http://www.ninebynine.org/#Contact
Received on Wednesday, 13 September 2006 14:55:46 GMT

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