Re: semantics of daml:equivalentTo [was: Comments on Annotated DAML 1.6]

"Peter F. Patel-Schneider" wrote:

> > There is
> > a reasonably well-defined meaning for equality (=identity =
> > equivalence) which is pretty much what Jeff says above: it means that
> > the terms refer to the same thing. So to assert
> >   equivalentTo(X, Y)
> > is to claim that X and Y have the same denotation. Now, this in turn
> > is just as clear or as murky as the notion of denotation is for X and
> > Y.
> >
> > Pat Hayes
> 
> It is my belief that Jeff's belief is that equivalentTO should be much more
> like the other option I outlined, namely that X is given the definition
> that Y has and that X can have no other definition.

I have to agree with Pat here.  To reiterate the points in my
message of the other day, what you're dealing with is a notion
of identity/equality across properties/relations/whatever.

To say (as Peter says) that 

  "namely that X is given the definition that Y has and that X
   can have no other definition"

is to say that X and Y have precisely the same properties (this is
Leibniz's Law).  Why is there a need to express this idea in other
than standard existing mathematical/philosophical terms???

  ...bill

-- 
Bill Andersen
Chief Technology Officer - Ontology Works
1130 Annapolis Road, Suite 203, Odenton, MD 21113
andersen@ontologyworks.com / 410-674-7600

Received on Friday, 13 October 2000 14:39:27 UTC