Re: DAML-S expressiveness challenge #1

[Ian Horrocks" <horrocks@cs.man.ac.uk>
To: "David Martin]

> What you really want to say is that that the class of
> persons who buy diapers is exactly the same as the class of persons
> who parented some other person. To do this you should use a
> sameClassAs assertion along the lines of (using a pseudo-syntax):
>

I think it's a good idea to get questions like this set out as clearly and
simply as possible before inventing new syntax or vocabulary for them.  If
you were using predicate logic or KIF, I imagine you'd arrive at something
like this:

for all persons x it is not true that:
    ((x bought diapers) and (x is not a parent))

With conceptual graphs it might be easier to read, but even this way it
doesn't seem too complex.  What we want is a way to define some kind of
relationship, property, or situation (take your pick according to
circumstances) that expresses the above.  (I know I am glossing over the
definitions of "bought diapers" and "is a parent"). So David's question
could be viewed as having two parts:

1) Is there a way to express the above assertion?  And if so,
2) Is there a way to define a new term as a shorthand for that expression?

I suggest that these questions should be answered before getting into
questions of classes of persons (Ian's suggestion, above) versus assertions
about persons (my example), for instance.

I just encountered DAML-S last night for the first time, so I have no
opinion on this specific question.  I certainly hope that 1), at least, can
be answered "yes".  The answer to 2) would be "yes" for conceptual graphs
(and KIF, I believe).

Forgive me if I have missed the point, since I am new to the list and to
this discussion.

Regards,

Tom P

Received on Monday, 9 July 2001 17:21:35 UTC