- From: Jonathan Borden <jonathan@openhealth.org>
- Date: Wed, 1 May 2002 17:54:33 -0400
- To: "Deborah McGuinness" <dlm@ksl.stanford.edu>, "Enrico Motta" <e.motta@open.ac.uk>
- Cc: <www-webont-wg@w3.org>
Enrico Motta wrote: > At 5:34 pm -0700 28/4/02, Deborah McGuinness wrote: > > > > > Can't one define existentially qualified range restrictions by having > >> local ranges + min-cardinality? Or are they something else? > > > >with universally qualified range restrictions one can say things > >such as "all my > >children are doctors" > >and with min cardinality one can say things such as "i have at > >least one child" > >but in combination that only allows one to say I have at least one child and > >ALL my children are doctors. > >This DOES imply that I have at least one child who is a doctor. > >BUT it does not allow you to state the full generality of > >existentially qualified > >range ... > ... At the same > time I suspect that the opposite is not true. If I don't have > universally quantified local range restrictions, I would not know how > 'to fake' them using existentially quantified local restrictions. > > Correct? At the A'dam F2F, we discussed the fact that the only thing that is _ever_ needed are local range restrictions, as global restrictions can be expressed as a "local" restriction on owl:Thing. Hence I'd favor only local restrictions, as these are, in my experience, alot easier to understand for most people, particularly those used to they way classes are defined for popular programming languages. Jonathan
Received on Wednesday, 1 May 2002 17:58:38 UTC