Re: The Q model

From: Lars Marius Garshol <larsga@ontopia.net>
Subject: Re: The Q model
Date: Thu, 04 Aug 2005 20:52:11 +0200

> 
> Hi Peter,
> 
> * Peter F. Patel-Schneider
> |
> | I am puzzled why you say that if RDF can be transformed into Q with
> | no loss of information then OWL/RDFS semantics can be ported to it.
> 
> Hmmm. I think probably you're reading more into this statement than I
> intended by it. Clearly, RDF represented in Q is still the same RDF,
> and so the same OWL/RDFS semantics will apply as when RDF is just
> triples, but, as you note below, this will be a semantics that ignores
> the two extra elements. 

This seems to be akin to extending propositional semantics to first-order
sentences by ignoring the quantifiers and variables.  I just don't see how it
is obvious that it will work.

> | Both RDFS and OWL have a non-trivial semantics that may not survive
> | the changes from simple statements to identified and situated
> | statements very well.  Do you have a fully-worked-out version of
> | RDFS and OWL in this arena?
> 
> No, I do not. I think I can see a way to take context into account,
> but I don't have this worked out, and it's definitely possible that
> taking the two extra elements into account will break it.

Yes, well then why the claim?

> | Similarly, how do the RDF semantic conditions play into the story,
> | particularly with the inclusion of contexts in the Q model?
> 
> I've not been able to work this out yet. This paper takes me to the
> point where I have RDF and Topic Maps in a single model, but no
> semantics for this unified model yet. One obvious next step is to
> create a unified semantics based on this model.

This seems to be just like saying that you have a syntax that marries
propositional temporal logic and higher-order predicate logic, but no semantics
for the combined syntax.  What makes you think that a reasonable combined
semantics is even possible?  

Note that I'm not saying that this is not possible.  I am instead saying that
you, as the proposer, need to show that it is indeed possible.

> -- 
> Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
> GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >

Peter F. Patel-Schneider
Bell Labs Research

Received on Thursday, 4 August 2005 21:13:44 UTC