Re: Some basic questions about OWL-Full

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Subject: Re: Some basic questions about OWL-Full
Date: Mon, 22 Oct 2007 22:12:00 -0400

> One point I have been confused about is the interplay between the  
> abstract syntax and OWL Full. I was under the impression that even  
> OWL full needs to be able to be expressed in the abstract syntax. But  
> the abstract syntax is such only trees of anonymous individuals are  
> possible to express, but not cycles. However, a cycle of blank nodes  
> *is* able to be expressed in RDF (= OWL Full?)
> 
> -Alan

The syntax for OWL Full is RDF triples.  Any set of RDF triples can be
considered to be an OWL Full KB.  The OWL Full semantic conditions then
work on this set of triples.  

If the set of triples "looks like" the translation of an OWL DL KB then
you can often think of the OWL Full KB as roughly equivalent to the OWL
DL KB.  However, if the set of triples doesn't look like a translation
then you generally can't use the OWL DL semantics to help you and you
have to go straight to the OWL Full semantic conditions.  In some cases
the meaning of the such OWL Full KBs may be counter-intuitive.

So, for example, if you have a cycle of blank nodes that use the OWL
syntax URIs, you may have to puzzle out its meaning.  (The cycle will
have a well-defined meaning in all cases, however.)  If the cycle of
blank nodes does not involve the OWL syntax URIs then its meaning is
probably close to what you might expect (provided that you understand
how blank nodes work in RDF).

peter

Received on Tuesday, 23 October 2007 08:39:02 UTC