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Re: Using rdf reification to nest statements in N3 like contexts

From: Graham Klyne <GK@NineByNine.org>
Date: Mon, 18 Mar 2002 09:16:49 +0000
Message-Id: <5.1.0.14.2.20020318091103.038b14f0@joy.songbird.com>
To: "Seth Russell" <seth@robustai.net>
Cc: "RDFIG" <www-rdf-interest@w3.org>
At 05:32 PM 3/17/02 -0800, Seth Russell wrote:
>I know.  But here, I though we were just talking about the syntax that would
>allow us to represent assertions in contexts; and in particular how you
>proposed to project those representations into RDF triples in section 6 of
>your note below.
>
>http://www.ninebynine.org/RDFNotes/UsingContextsWithRDF.html#xtocid-63039726
>
>My point is that If we use your proposed syntax, then we are severely
>limited because the tuples in any context are dependant on the level of
>nesting.  If we want to talk about a inner nest, we can only refer to it
>using that same tree nesting.

I acknowledge the problems of the encoding syntax that you raise... in 
particular that one cannot just "cut-and-paste" between graph 
representations in this form.  That section was deliberately an 
afterthought, an attempt to show how reification-quads might be used, and 
not a prerequisite for any of the preceding thoughts.  Other encodings are 
surely possible, and in many ways better.  I'm not too bothered by the 
syntax here - RDF syntax is ugly anyway.  For me, it's the graph and its 
associated semantics that are interesting.

...

>You mean like KIF.  Thing is that mentography is not a language, rather it
>is just grammar; it is pure uninterperted  syntax.  It's just labeled
>directed graphs.  It carries with it no commitment whatsoever to any
>ontology, logical primitives, or semantics.

Hmmm... I take issue with that -- without semantics, how is it a language?

But...

>Please see the new mentograph:
>http://robustai.net/mentography/mentography_example_1.gif

... ah, now I see.

>When I introduced context into the diagrams I naturally started combining
>labeled directed graphs with Venn diagrams.  There is some precedence for
>this see "Projections in Venn-Euler Diagrams" :
>
>http://www.it.bton.ac.uk/research/vmg/papers/Projections.pdf
>
>But the mentograph below, which I made to grok your proposal,  was just
>simple RDF triples.  You should have been able to read the RDF Ntriple
>syntax directly off the graph: one arrow - one Ntriple.   If you can't
>interpret it, then you can't interpret Ntriples.   The question remains: is
>this what you are proposing?
>
>http://robustai.net/mentography/context_n3_rdf_liar_comparison1.gif

Yes, that's what I meant (apart from possibly not using rdf:Bag as the 
container type for a context).

And now I see your point.  Yes, it's probably OK to use the container as 
the indicator of nesting;  one can protect the contents of inner containers 
when "unwrapping" and asserting an outer context.


#g



-------------------
Graham Klyne
<GK@NineByNine.org>
Received on Monday, 18 March 2002 05:07:34 GMT

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