- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Thu, 02 May 2002 11:38:05 -0400
- To: jos.deroo.jd@belgium.agfa.com
- Cc: www-rdf-logic@w3.org
From: "Jos De_Roo" <jos.deroo.jd@belgium.agfa.com> Subject: Re: A Single Foundational Logic for the Semantic Web Date: Thu, 2 May 2002 17:06:14 +0200 > > > > > A simple analysis shows than every formula has to exist in every > model. > > > > > > the simplest formula I can imagine is the empty graph { } > > > and it doesn't have a model/interpretation (it's simply false) > > > how could it exist in every model??? > > > > > > -- > > > Jos > > > > > > > Simply. Remember that these formulae are not asserted, i.e., they are > not > > triples themselves, they are just something like quoted expressions. (Of > > course, there are the triples that represent them *are* asserted triples > in > > the graph. So the formula > > > > {} > > > > exists in every model/interpretation, but is not a member of log:Truth. > > So one could see {} as a name used in RDF (meta) language. > That name corresponds with the empty graph in RDF (object) > language (and has no RDF model/interpretation). We should > never assert both in the same engine. > > -- > Jos Actually I misspoke. The empty graph {} is the empty conjunction, which is, of course, always true, and thus {} is a member of log:Truth. peter
Received on Thursday, 2 May 2002 11:38:15 UTC