W3C home > Mailing lists > Public > www-rdf-interest@w3.org > December 2001

Re: what RDF is not (was Re: RDF/XML Syntax Specification (Revised) W3C Working Draft published)

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Mon, 31 Dec 2001 11:03:21 -0500
To: jos.deroo.jd@belgium.agfa.com
Cc: bwm@hplb.hpl.hp.com, mmoran@netphysic.com, dave.beckett@bristol.ac.uk, www-rdf-interest@w3.org
Message-Id: <20011231110321Y.pfps@research.bell-labs.com>
From: jos.deroo.jd@belgium.agfa.com
Subject: Re: what RDF is not (was Re: RDF/XML Syntax Specification (Revised) W3C Working Draft published)
Date: Fri, 21 Dec 2001 23:40:22 +0100

> [...]
> 
> > I don't think that your manipulations are permissable, at least not in
> > RDF(S).
> >
> > In particular, entailment is a meta-theoretic notion, and is not part of
> > the syntax of a logical formalism.  Some logical formalisms can turn some
> > or all entailments into implication, but not all can.
> 
> classical logic can

Sure, but how did classical first-order logic get into the picture?

> > In any case, I'm still confused as to what you were trying to demonstrate.
> > Perhaps you were trying to show that RDF(S) is a fragment of first-order
> > logic.
> 
> We just do and don't do something with RDF graphs
> e.g.
> 
> given RDF graph1
> 
>   _:child gc:childIn _:family .
>   _:parent gc:spouseIn _:family .

OK

> and RDF graph2
> 
>   _:aaa gc:parent _:bbb .

OK

> all the rest is about what we do and don't do with these RDF graphs
> 
>   don't assert graph1
>   don't assert graph2
>   state that bnode _:child denotes same thing as bnode _:aaa
>   state that bnode _:parent denotes same thing as bnode _:bbb
>   state that graph1 classic-logically implies graph2

How?  That is, what formalism are you using to do this in?


> one way to write this down is
> 
>   { ?child gc:childIn ?family . ?parent gc:spouseIn ?family }
>     log:implies { ?child gc:parent ?parent } .
>
> where ?child, ?family and ?parent are universally quantified
> (although, if there would have been other bnodes in graph2,
> they would remain existentially quantified)

Again, what formalism is this?  Is it a syntax for first-order logic?  If
so, what is the syntax?  If not, what is it?  If you are making some
meta-theoretic claim, then what is the claim?

> now we treat that as another RDF statement
> (but again, not necessarily asserted)
> so that we can repeat the same story

This is not an RDF statement, unless you are using reification somehow.  If
you are, then what syntax is this?

> I don't know what one could claim from this
> w.r.t. FOL (or SWOL)

Then why do the exercise?  I really am puzzled as to what point you are
trying to make.

> --
> Jos

peter
Received on Monday, 31 December 2001 11:04:11 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:51:52 GMT