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

Re: Possible semantic bugs concerning domain and range

From: pat hayes <phayes@ai.uwf.edu>
Date: Fri, 27 Sep 2002 22:54:19 -0500
Message-Id: <p05111b1cb9bad712d828@[65.217.30.172]>
To: "Christopher Welty" <welty@us.ibm.com>
Cc: www-webont-wg@w3.org

>(This may sound like I'm speaking for Pat, but actually I'm trying to
>verify if I understand his position)

Heaven forfend that you should ever find yourself speaking for me, Chris.

>
>I think what I'm getting out of trying to ingest the discussion is that
>Pat wants the semantics of ranges to be something like, in a "free
>wheeling" syntax:
>
>Property(p) -> EXISTS c . Class(c) AND Range(p,c)
>Property(p) AND Range(p,c1) AND Range (p,c2) -> c1=c2
>p(x,y) AND Range(p,c) -> c(y)
>
>So he wants there to be one and only one class that is THE range of a
>property.

No, no. Im sorry I ever said this awful thing. I was trying to convey 
an intuition but I did it badly. Better, what Im trying to say is 
that I want it to be possible to have a *particular set* of ranges. I 
don't mind if that set is closed under intersections, even. But I do 
mind if Im forced to say that a set is a range just because all the 
values of the property are in it. That should be a necessary but not 
sufficient condition to be a range. I want it to be possible to 
restrict rangehood to some special class of classes.

>  Your entailment below should still be OK, ie
>
>Subclass(c1,c2) AND Range(p,c1) AND p(x,y)  |= c2(y)
>
>BUT NOT:
>Subclass(c1,c2) AND Range(p,c1) |= Range(p,c2)

Right on that.

>
>If this is an accurate account of Pat's position, then the argument
>against the entailments in OWL regarding superclasses of property ranges
>is that it abuses the Range relation between a property and a class, and
>violates the uniqueness axiom above.

The former, yes; latter, no. Never mind about uniqueness, sorry I 
ever gave that impression.

Pat


-- 
---------------------------------------------------------------------
IHMC					(850)434 8903   home
40 South Alcaniz St.			(850)202 4416   office
Pensacola              			(850)202 4440   fax
FL 32501           				(850)291 0667    cell
phayes@ai.uwf.edu	          http://www.coginst.uwf.edu/~phayes
Received on Friday, 27 September 2002 23:54:02 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:57:52 GMT