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Re: Is "Model" part of the RDF model?

From: Jonas Liljegren <jonas@rit.se>
Date: 22 Oct 2000 11:40:58 +0200
To: "McBride, Brian" <bwm@hplb.hpl.hp.com>
Cc: rdf@uxn.nu, www-rdf-interest@w3.org
Message-ID: <87g0lp8b85.fsf@astral.paranormal.se>
"McBride, Brian" <bwm@hplb.hpl.hp.com> writes:

> > We only have to create the class Model and make it a subClassOf
> > Container.  Nothing strange about that.
> 
> Yup - this is similar to what Graham is doing with contexts and
> the bag of statements idea.
> 
> The difference between this and the model idea used in SiRPAC
> and Jena is that the API style model contains statements.
> Contexts, bags and I presume the 'model' container Jonas
> proposed contains reified statements.
> 
> I'm struggling to understand whether this matters.

As I understand it:

Statements are not resources.  They do not exist (as resources) in the
RDF diagram.  Reified statements was invented as a way to make
statements resources, so that we can say things about them.

The RDF M&S explains that you can have the statement resource without
having the actual statement.  This is why many DB implementations of
RDF uses the 'fact' boolean as an indication if the statement is
stated in the model, or only just exists there as a resource.

Wraf and other RDF implementations automaticly creates a resource for
every statement.  This is safe because it doesn't add any information,
except that it gives the statement an URI.



I have no intention to actually write out the reified statements of a
model as a RDF/XML serialization.  They just exist there implicitly to
let you know what the subject, predicate and object of a specific
statement are.  Neither does the container (with it's _1, _2, ...)
actually exist.  It's just a way to represent the model in RDF.


-- 
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Received on Sunday, 22 October 2000 05:45:08 GMT

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