Re: LANG: compliance levels

On May 2, Jonathan Borden writes:
> Ian Horrocks wrote:
> >
> > I would suggest that where universal quantification is being widely
> > used in practice, it is either as a result of its being the only
> > available option and/or the fact that many users assume an implicit
> > existential - it never occurs to them that people all of whose
> > children are doctors may not have any children at all (I would hardly
> > bother telling you what type their children must be if they don't have
> > any children, would I?).
> >
> 
> Hmm. What about combining toClass with minCardinality, so that there would
> have to be, e.g., at least one child, and that child would have to be a
> doctor -- or would that just be a minCardinalityQ?

No. As I think Deb already pointed out, asserting (minCardinality 1 P)
along with (toClass P C) means that there can never by any Ps that
are not Cs. Saying (minCardinalityQ 1 P C) means that there is at
least one P that is a C, but says nothing about the existence or
otherwise of other Ps that are not Cs. So, (minCardinalityQ P 1 C) is
equivalent to (hasClass P C). As I mentioned at one of the earlier F2F
meetings, the Q restrictions are the most general and can capture both
hasClass and toClass: (maxCardinalityQ 0 P (not C)) is equivalent to
(toClass P C).

Ian

> 
> Jonathan