Re: A Single Foundational Logic for the Semantic Web

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