Re: defaults

"Peter F. Patel-Schneider" wrote:

> All that said, there will be a part of OWL that is not part of the logic
> underlying OWL, or, at least, that I hope will not be part of the logic
> underlying OWL.  This is precisely the part of OWL that deals with
> ontologies (or documents, or ...).  Yes, this part of OWL interacts with
> the logic underlying OWL, and, maybe, there could be a formal treatment of
> it, but it does not inhabit the same conceptual space as interpretations,
> models, and entailment.

I may be misunderstanding Peter here, but I *think* he just said that OWL
statements should exist in some rarified space that is NOT the space of real
documents and real manipulations of the real web.  Whether Peter holds this
position or not, there certainly are those who do.  I believe that this position
is fundamentally at odds with our job as WebOnt-WG and will run into trouble as
soon as we begin to deal with things like 404 and changing web pages and digital

> Such constructs (e.g., daml:imports) can indeed have impact on the
> behaviour of OWL implementations, of course, but this is generally in terms
> of determining what pieces of syntax are fed into an OWL reasoner, and
> definitely not in terms of affecting the OWL reasoner in any other way.

What happens when the assertion that the OWL reasoner used to draw its conclusion
is retracted by the previously asserting page?

> It may turn out that there is a way of making some version of defaults fit
> into this part of OWL.  I expect that any such version of defaults will be
> a very weak (or very strong) version of something like input completion.

It may well turn out that this is so.  But that part will have these issues
(nonmonotonicity, literal incorporation of syntax, etc.) whether we fit defaults
in there or not.  It is also where the asserter lurks....OWL statements aren't
true or false, they're asserted (by an agent or by the resolvent of a url or by a
document) or not.


Received on Tuesday, 22 January 2002 16:31:43 UTC