- From: Sigfrid Lundberg, Lub NetLab <siglun@gungner.lub.lu.se>
- Date: Fri, 11 May 2001 15:59:33 +0200 (MET DST)
- To: Enrico Franconi <franconi@cs.man.ac.uk>
- cc: www-rdf-logic@w3.org
On Fri, 11 May 2001, Enrico Franconi wrote: > If you have a propositionally closed representation language, then > having a not-strict-sub-class-of allows you to have the > strict-sub-class-of as well. So there is NO trading inferability > against expressiveness. You're obviously correct. An obvious follow-up question is: Why doesn't daml do it this way? Or does it, but I'm not able to see it (because I might not be able to recognize a "propositionally closed representation language" when I see it ;). > This is how you could represent your example: > > Introduce first a freshly new primitive class "non-sub-title". > Add the following axioms: > > sub-title is-a-not-strict-sub-class-of title. > title is-a-not-strict-sub-class-of (sub-title or non-sub-title). > non-sub-title is-a-not-strict-sub-class-of ((not sub-title) and title). > > This implies: > sub-title is-a-strict-sub-class-of title > > cheers > -- e. Have a nice weekend Sigge
Received on Friday, 11 May 2001 09:47:34 UTC