Re: Joint Committee telecon today (semantics for domain and range)

From: Peter F. Patel-Schneider (
Date: 01/09/01

From: Dan Connolly <>
Subject: Re: Joint Committee telecon today (semantics for domain and range)
Date: Tue, 09 Jan 2001 12:59:06 -0600

> "Peter F. Patel-Schneider" wrote:
> > 
> > As promised, I have a new version of the semantics for DAML+OIL.  It is
> > enclosed below.
> > 
> > The ONLY substantive changes are the last two lines, which read
> > 
> >         <domain,?P,?C>  if <x,y> in IR(?P) then x in IC(?C)
> >         <range,?P,?C>   if <x,y> in IR(?P) then y in IC(?C)
> > 
> > NOTE:  This does not correspond to the current RDFS intended meaning for
> > these constructs.
> Intended by whom? ;-)

I meant intended meaning in the sense that it is what is alluded to in the
RDFS documentation, but not fully specified there. 

> It corresponds to what I intend, and at least one of the RDFS
> editors (Guha). It does not correspond to the way some
> folks have interpreted the RDFS spec.
> I should double-check that this is on the RDF IG issues list...
> no time just now. Please remind me if you get a chance...

The RDFS documentation has a completely different meaning for multiple
domains.  I know that there appears to be consensus to change RDFS in this
manner, but I think that we need to attach caveats to every definition of
domain and range until the change is made.  :-(

> Er... substantively: the implication should go both ways, no?
> 	<x,y> in IR(?P) iff x in IC(?C)
> No... I guess that would mean that these are total functions.
> (sorry, no time to think carefully about it.)

iff would mean something completely different.

> -- 
> Dan Connolly, W3C


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