From: Pat Hayes (phayes@ai.uwf.edu)
Date: 10/25/01
> > >> Sorry to be dense, but how does one state "there is something colored >> >> red" in DAML+OIL? >> > >> >The simple answer is that you can't without either naming it (i.e., >> >asserting that some named individual is red) or connecting it to some >> >named individual via properties. This "collapsed model property" is >> >one of the basic properties of description logics on which their >> >decision procedures depend. >> >> Hmm. This seems easy in RDF: >> >> _:xxx hasColor Red . >> >> That would seem to imply that RDF can express something that DAML+OIL >> cannot express! Which is fine, I guess, but it doesn't jibe with what >> I had (perhaps naively) thought was the intended relationship between >> RDF/S and DAML+OIL. > >I would very much like to see this issue resolved. > >However, it seems to me that cardinality constraints provide us with the >same (or at least analogous) issues regarding bindings to query >variables in query results. I.e., does a query that asks for all the >parents of Joe (as described in my previous message), to a KB that does >not name the parents of Joe get back two bindings to constants created >by the query answering agent to represent the parents of Joe or does it >get back no bindings plus an indicator that there are exactly two >answers to the query? Or should there be no difference between these cases? (I certainly wouldn't expect the query-answering system to start giving me *numbers*.) Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
This archive was generated by hypermail 2.1.4 : 04/02/02 EST