W3C home > Mailing lists > Public > www-webont-wg@w3.org > April 2002

RE: SEM: semantics for current proposal (why R disjoint V?)

From: Ian Horrocks <horrocks@cs.man.ac.uk>
Date: Tue, 16 Apr 2002 23:23:43 +0100
Message-ID: <15548.42095.718451.313189@merlin.oaklands.net>
To: Pat Hayes <phayes@ai.uwf.edu>
Cc: www-webont-wg@w3.org
On April 8, Pat Hayes writes:
> >On March 22, Jeremy Carroll writes:
> >>  >
> >>  > [1]
> >>  http://www-lti.informatik.rwth-aachen.de/~clu/papers/archive/lutzdiss.pdf
> >>
> >>
> >>
> >>  Ian,
> >>
> >>  I don't think I have time to read 225 pages ... :(
> >>
> >>  Is there a shorter version of the central argument?
> >
> >The key point is that without separation of properties, when you
> >negate restriction classes, e.g., (hasClass age >=21) you get (toClass
> >age (union <21 Thing)), which breaks the separation of the datatype
> >and abstract domains which is itself required in order to allow
> >datatype reasoning to be separated from class based reasoning.
> 
> Wait. That seems circular. Isn't this supposed to be an argument for 
> why we need to separate datatype reasoning from class-based reasoning 
> in the first place? Suppose we just say that, OK, they are not 
> separated. Then the above argument says that if we have negation then 
> they are not separated. But we already knew that, right?

The question I thought I was answering was, why separate properties as
well as domains? The above argument says that you need to separate
the properties in order to keep the domains separate.

Ian

> 
> Pat
> 
> -- 
> ---------------------------------------------------------------------
> IHMC					(850)434 8903   home
> 40 South Alcaniz St.			(850)202 4416   office
> Pensacola,  FL 32501			(850)202 4440   fax
> phayes@ai.uwf.edu 
> http://www.coginst.uwf.edu/~phayes
> 
Received on Tuesday, 16 April 2002 18:26:29 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:57:49 GMT