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RE: Rules WG -- draft charter -- NAF

From: Wagner, G.R. <G.R.Wagner@tm.tue.nl>
Date: Tue, 18 Nov 2003 15:35:02 +0100
Message-ID: <D0D13B0440FC1F4995BC4CD7F84A3A4216490C@tmex2.campus.tue.nl>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, <stefan@ISI.EDU>
Cc: <www-rdf-rules@w3.org>

> Not so fast.  What if it is difficult to determine just what objects
> (belonging to a particular class) exist?  Then what does 
> closing (a class) mean?

There are two issues:

1) Closing a class/predicate, such as with N3's "definitiveDoc"
declaration. In such a case (of typically administrative information)
you don't have to deal with indefinite information and applying NAF 
to such a predicate corresponds to classical negation.

2) The semantics of NAF in the presence of indefinite information:
in this case there are still some research issues concerning the
proper concept of preferred/"minimal" model, but clearly NAF(P(a))
fails (cannot be inferred) on the basis of P(a) v P(b).

Received on Tuesday, 18 November 2003 14:25:43 UTC

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