- From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
- Date: Tue, 15 Oct 2002 23:47:39 +0200
- To: "Dan Connolly <connolly" <connolly@w3.org>
- Cc: Ian Horrocks <horrocks@cs.man.ac.uk>, Pat Hayes <phayes@ai.uwf.edu>, www-webont-wg@w3.org, www-webont-wg-request@w3.org
>> >> Range(P, A) -> (forall x,y P(x,y) -> A(y) ) >> >> >> >> You want >> >> >> >> Range(P,A) <-> (forall x,y P(x,y) -> A(y) ) >> >> >> >> They are about equally clear and intuitive; but the latter rules out >> >> some possibilities which the former permits. I believe that all the >> >> 'intuitive' entailments that people want in fact hold in both these >> >> cases; and that the former is therefore to be preferred. >> > >> >I am agnostic about which of these is to be preferred - as a humble >> >engineer, all I need to know is which one it is so that I have a clear >> >spec to which I can build my systems. > >I'm kinda agnostic too... I was leaning toward the IF, rather >than the IFF... I'm not agnostic at all... i.e. I can't see how to write (forall x,y P(x,y) -> A(y)) -> Range(P,A) in Horn-clauses or in Datalog (although I like nested implications in propositional proof arguments) [...] -- , Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Tuesday, 15 October 2002 17:48:19 UTC