DAML: About Thing, Nothing and the "universe of discourse"

The DAML-OIL suggestions defines Thing as the union of Nothing and the
complement of Nothing and stated - but does not explains why - that this
provide some benefits regarding semantics?

My current perspective is from outside DAML and DL so I hope that the
following make sense and is not too misaligned with the proposal::

I would like to see the ability to (on a individual basis) express which
nodes/classes/instances/etc are in the (current) universe (domain) of
discourse and which are not.

For this one approach is to be able to specify what is "outside", for
which it appears that it would be a good idea to define Nothing simply
as the complement of Thing with the usual IC(Thing) = DD.... Than
individuals of Nothing would be outside the universe of discourse.

/M. Christensen, DK

Received on Wednesday, 6 December 2000 10:17:02 UTC