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Resolution of: #rdfms-identity-anon-resources

From: Graham Klyne <GK@NineByNine.org>
Date: Tue, 02 Oct 2001 13:27:45 +0100
Message-Id: <5.1.0.14.2.20011002124353.00a02ec0@joy.songbird.com>
To: RDF core WG <w3c-rdfcore-wg@w3.org>
With respect to the issue:
[1] http://www.w3.org/2000/03/rdf-tracking/#rdfms-identity-anon-resources

Being a revision of my previous message:
[2] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001Aug/0030.html

And citing the model theory document:
[3] http://www.w3.org/TR/2001/WD-rdf-mt-20010925/

I propose the following resolution text:

[[[
1. Resources that are described but not named in an XML serialization (by 
rdf:ID or rdf:about) are represented in an RDF abstract graph by nodes that 
do not have any associated URI.  Such nodes, called bNodes (from blank 
nodes) are thereby distinguishable from other described resource nodes, 
which do have an associated URI-reference label.

To directly address the question of the issue:  a so-called anonymous 
resource has no URI.

2. To reflect un-named descriptions in N-triples, local names must be
introduced (i.e. of the form '_:name').  These names are not URIs, and
their scope is the N-triples document in which they appear.

3. In normal use, the meaning of bNode is to assert the existence of at 
least one resource which is the subject and/or object of properties as 
indicated by the graph.  This is covered more formally by the Model Theory 
[3], section 2.  See also the anonymity lemmas in section 3.2.

NOTE:  it has been proposed that the RDF graph syntax can be used for form 
a query, in which bNodes may be interpreted as query variables.  This 
resolution confirms that bNodes can be distinguished from other labelled 
nodes within the graph syntax, but is silent about if and how the graph 
syntax might be used to represent a query.
]]]

#g


------------
Graham Klyne
(GK@ACM.ORG)
Received on Tuesday, 2 October 2001 08:31:59 EDT

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