Re: DAML-S expressiveness challenge #1

I'm not exactly sure what David Martin needs to model
in his work with DAML-S, but here's a simple example
that I think brings out the problem or at least a related
one.  I'm basing this on an old example from KL-ONE days:

   a person is a thing with
       one home address of type address
   a worker is a person with 
       one office address of type address
   a homeworker is defined as a worker
       who's home address and office address are the same.

in logic we would (partially) model this as 

   homeworker(X) <-> person(X), homeaddr(X,A), officeaddr(X,A)

What's missing in DAML+OIL (as far as I understand) is the ability
to express the equality constraint between the values of the two
properties which is no nicely done with variables and unification
in many languages.

--
 Tim Finin, Prof Computer Science & Electrical Eng, Director Inst. for Global
 Electronic Commerce, U Maryland Baltimore County, 1000 Hilltop, Baltimore MD
 21250. mailto:finin@umbc.edu 410-455-3522 fax:-3969 http://umbc.edu/~finin/