- From: pat hayes <phayes@ai.uwf.edu>
- Date: Fri, 13 Oct 2000 14:12:34 -0500
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- Cc: www-rdf-logic@w3.org
>From: pat hayes <phayes@ai.uwf.edu> >Subject: Re: semantics of daml:equivalentTo [was: Comments on >Annotated DAML 1.6] >Date: Fri, 13 Oct 2000 12:00:45 -0500 > > > >From: Jeff Heflin <heflin@cs.umd.edu> > > >Subject: Re: semantics of daml:equivalentTo [was: Comments on > > >Annotated DAML 1.6] > > >Date: Thu, 12 Oct 2000 15:29:56 -0400 > > > > > > > I'd just like to elaborate on Jim's message. I believe that >equivalentTo > > > > is the DAML version of the SHOE <DEF-RENAME> element. In SHOE, > > > > DEF-RENAME allows an ontology to provide an alias for a term defined > > > > elsewhere. Essentially, it means that both terms reference the same > > > > concept, and thus any assertion that is made using one term >is also true > > > > if the other term was substituted in its place. This is really easy to > > > > implement: you keep a hash table that matches aliases with the base > > > > terms (used in the original definitions) that they renamed, and upon > > > > parsing a document or issuing a query you can perform the necessary > > > > substitutions to rephrase it in only base terms. > > > > Jeff > > > 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. Yes, but the distinction between this version and a simple assertion of equality lies in what might called the definitional force rather than the propositional content. I agree that this is important, even central, for DAML in the long run, but in the short run I'd like to get the simple stuff clearly defined. BTW, I think that what Jeff really, really means is something like your 'strong' option, but restricted to one webpage. So it is strong but also 'local'. However I confess that I really have no clear idea what this actually means. 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 Friday, 13 October 2000 15:09:45 UTC