Re: ANN:

On 4 Jun 2009, at 12:18, Toby Inkster wrote:
> On Thu, 2009-06-04 at 00:54 +0100, Richard Cyganiak wrote:
>> The general RDF graph has the shape
>> A:  <U1> owl:sameAs <U1>, <U2>, <U3>, <U4> .
> Oh yes, another thing: saying the above, with OWL reasoning in place  
> is
> equivalent to saying:
>  B:  <U1> owl:sameAs <U1>, <U1>, <U1>, <U1> .

Naming the two above statements A and B it is true that when A is true  
so is B. But clearly there is a difference in sense, as Frege was  
forced to admit over 100 years ago, if I remember my logic correctly.  
This is the case since the information content of B is close to 0,  
whereas A could come as a surprise, and certainly can teach one  
something new. It can produce a cognitive change in the believer.

The way to think of it is that when you write one of the above  
sentences you are writing these statements down using precise URIs,  
thought of as Strings here. The sentences themselves cannot be  
understood without those syntactic tokens. Each of these URIs refers  
to an object in reality, but each one does so in a different way. In  
the case of http URIs this is quite evident: dereferencing each one  
gets one to a different representation, which can be thought of as  
defining or contributing to the sense of the URI in what could be  
called a canonical way.

So in short there is no need to use URI strings to make statements  
about owl sameas


Social Web Architect
Sun Microsystems		

Received on Thursday, 4 June 2009 11:13:55 UTC