Re: LANG: closing issue 4.6 (was Re: ADMIN: Draf agenda for July 25 telecon)

Oh yes, of course you're right. That's what I get for opening my mouth
without thinking things through.

I'm beginning to agree that option 2 is the right semantics for these
things, but I still need to examine a few use cases and consider all the
consequences. Perhaps we could meet at AAAI sometime to discuss?

Jeff

"Peter F. Patel-Schneider" wrote:
> 
> From: Jeff Heflin <heflin@cse.lehigh.edu>
> Subject: Re: LANG: closing issue 4.6 (was Re: ADMIN: Draf agenda for July  25     telecon)
> Date: Wed, 24 Jul 2002 13:57:09 -0400
> 
> > Peter,
> >
> > Thanks for this message. I think it helps clarify the issue. To further
> > elucidate things, could you answer a question I have about option 2?
> >
> > It seems to me the option 2 leads to non-monotonicity. Consider the
> > following classes with extensions:
> >
> > foo type Class.
> > bar type Class.
> > A type foo.
> > B type foo.
> > A type bar.
> > B type bar.
> >
> > Since sameClassAs only means that two classes have the same extension,
> > then foo sameClassAs bar is a valid entailment, isn't it?
> 
> No.  There are interpretations of the above KB where foo and bar have
> different extensions.  All that is known is that the denotations of both A
> and B belong to both foo and bar.
> 
> Similarly,
> 
>   John friend Peter .
> 
> does not entail that John belongs to the class of objects that have at most
> one friend.
> 
> [...]
> 
> > Jeff

Received on Friday, 26 July 2002 10:57:47 UTC