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Re: semantics status of RDF(S)

From: Aaron Swartz <aswartz@swartzfam.com>
Date: Tue, 03 Apr 2001 18:36:41 -0500
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
CC: RDF Logic <www-rdf-logic@w3.org>
Message-ID: <B6EFB4F9.83FF%aswartz@swartzfam.com>
Peter F. Patel-Schneider <pfps@research.bell-labs.com> wrote:

> We can then transfer negated statements via RDF, but RDF will
> get in the way by providing its own (incompatible) meaning for the triples
> that encode negation.  It would be much better if RDF would stay out of the
> way, and not provide any meaning for these triples, but that is not within
> the philosophy of RDF.

I've heard this argument before (from you, I'm pretty sure), and I believe
it is simply false. You're forgetting reification. Saying negation, truth,
etc. works just fine in RDF. Simply reify. Here's how it would be in XRDF:

<rdf:Description>
  <negation rdf:resource="#s"
</rdf:Description>

<rdf:Description rdf:about="#s">
  <rdf:subject rdf:resource="mailto:pfps@research.bell-labs.com" />
  <rdf:predicate rdf:resource="http://example.org/confusedAbout" />
  <rdf:object>reification</rdf:object>
</rdf:Description>

Or in English:

The thing that is the negation of the triple
{mailto:pfps@research.bell-labs.com confusedAbout "reification}.

I think N3 does it like this:

[ :negation 
    { <mailto:pfps@research.bell-labs.com> :confusedAbout "reification" .}
]

There is no problem. Since refication is used, RDF does not assert the
negated triple. Instead, it is merely in "quotes" and no meaning is
assigned. All I know is that you mentioned the statement, but I do not know
that you have asserted it.

The solution to "or" is similar (I believe "or" is what you asked about last
time). 

Does this solve the flaw you see?

-- 
[ Aaron Swartz | me@aaronsw.com | http://www.aaronsw.com ]
Received on Tuesday, 3 April 2001 20:37:30 GMT

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