- From: pat hayes <phayes@ai.uwf.edu>
- Date: Fri, 14 Mar 2003 10:32:40 -0600
- To: Sean Bechhofer <seanb@cs.man.ac.uk>
- Cc: <www-webont-wg@w3.org>
>On Thu, 13 Mar 2003, Dan Connolly wrote: > >> >> On Thu, 2003-03-13 at 10:47, Ian Horrocks wrote: >> > I know this is rather last-minute, but I would like to propose a >> > couple of small simplifications to the language that would >> > significantly improve ease of implementation of datatype reasoning in >> > both DL and Lite. >> > >> > 1. Change the specification of cardinality constraints so that they >> > can only be applied to individual valued properties and not to data >> > valued properties. This seems to be a relatively small loss as most >> > data valued properties turn out to be functional, and it is hard to >> > think of realistic examples where local/arbitrary-valued cardinality >> > constraints are required. >> >> I can support going to 0/1/many. But constraining a property >> to be functional is a cardinality constraint, no? >> I don't think I'm quite clear on what you're after. > >I think that what Ian is suggesting that you're still allowed to assert >whether a data valued property is functional or not, but that arbitrary >cardinality constraints involving data valued properties can't be used in >descriptions. So, for example, we can still say that age is functional, >and thus everyone can only have at most one age, but we can't form a >description of: > >"people who have at least three values for property x." > >where x is a data valued property. I, too, struggle to think of an example >where one would actually want to use such a construct (but am open to >suggestion).... People who own three or more homes, people with at least three sources of income, people with at least three children, people with with at least three nationalities, people who have travelled to more than three foreign nations during the last six months,.... Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes s.pam@ai.uwf.edu for spam
Received on Friday, 14 March 2003 11:32:26 UTC