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Re: A Rough Guide to Notation3

From: Seth Russell <seth@robustai.net>
Date: Sat, 24 Aug 2002 09:18:29 -0700
Message-ID: <005d01c24b89$e32a5400$657ba8c0@c1457248a.sttls1.wa.home.com>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, "Sandro Hawke" <sandro@w3.org>
Cc: <sean@mysterylights.com>, <www-rdf-interest@w3.org>

From: "Sandro Hawke" <sandro@w3.org>

> Can't we just just disallow RDF graphs which describe self-referencial
> sentences (or at least self-negating) ones?
>
> One possible way to restrict self-referencial sentences is to say
> something like: for all X Y Z in U, the sentence (X Y Z) exists in
> R(U) but not U.  R(U) is a superset of U and exists for all U.  (There
> is some U0 which does not contain any sentences.  R(U0) constains
> sentences, but not sentences about sentences.  R(R(U)) contains
> sentences about sentences, but not sentences about sentences about
> sentences.)
>
> Is there some reason we need any other kind of sentences to exist?

I don't see why we cant just make any sentence that has itself as it's own
subject be a syntax error at parse time.  This probably doesnt have much to
do with RDF, since RDF does not provide an identity for triples; but an
application (such as sailor agents) could generate a serial number for every
RDF triple and allow for a language to use that serial number to make
statements about statements.  When we parse such a language into a graph and
find that the serial number of {S1 p o} is S1, we raise a syntax error.

Is there some reason we need a sentence to be it's own subject?

Seth Russell
http://robustai.net/sailor/
Received on Saturday, 24 August 2002 12:19:15 GMT

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