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Re: reification vs. named graphs

From: Story Henry <henry.story@bblfish.net>
Date: Tue, 14 Aug 2007 15:17:34 +0200
Message-Id: <11D96F3A-3163-4F51-A615-11438544200E@bblfish.net>
Cc: "Bijan Parsia" <bparsia@cs.man.ac.uk>, "Michael Schneider" <m_schnei@gmx.de>, semantic-web@w3.org, jjc@hpl.hp.com
To: "Danny Ayers" <danny.ayers@gmail.com>

There is clearly a relation between graphs and their literal  
Perhaps something like the relation between a foaf:Person and their  

[] a Graph;
    n3:literal "_:it <http://purl.org/dc/elements/1.1/title>  
'Interesting Times'";
    = { [] dc:title "Interesting Times" };
    = "_:it <http://purl.org/dc/elements/1.1/title> 'Interesting  
Times'"^n3:literal .

here n3:literal would be an inverse functional property relating  
graphs to strings.
There can clearly be a very large number of ways of linking a graph  
to a literal. Just think
of all the different encodings, and all the different orderings of  
the statements therein.

So what are graphs? Some would say sets of interpretations or sets of  
possible worlds. I am not sure what the named graph proposal does.

It is clear that saving the graphs in a triple database the way one  
saves other triples, does make it easier to work with them. It is  
easier to  merging, search and querying graphs if one does not first  
have to deserialise a rdf/xml representation. So I do like the { }  
notation in N3.


On 14 Aug 2007, at 13:00, Danny Ayers wrote:
> On 14/08/07, Bijan Parsia <bparsia@cs.man.ac.uk> wrote:
>> On 14 Aug 2007, at 10:24, Story Henry wrote:
>>> Does the current standard not in fact allow graphs through the use
>>> of XML/RDF literals? If an RDF document contains a relation
>>> pointing to an RDF/XML literal, then that RDF/XML is playing
>>> somewhat the role of a graph, no? I mean it is opaque in the same
>>> way a graph is...
>> [snip]
> [snip]
> I brought this up somewhere fairly recently and someone (thought it
> might have been idickinson on #jena, but apparently not...), pointed
> me to Jena Assemblers  which use this kind of thing, e.g.
> eg:literal-content-example
>     ja:literalContent "_:it dc:title 'Interesting Times'"
>     .
> http://jena.sourceforge.net/assembler/assembler-howto.html
>> A solution, nevertheless, worth investigating.
> Yup.
> Cheers,
> Danny.
> -- 
> http://dannyayers.com
Received on Tuesday, 14 August 2007 13:34:21 UTC

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