- From: Dieter Fensel <dieter.fensel@deri.org>
- Date: Thu, 09 Feb 2006 14:54:16 +0100
- To: Michael Kifer <kifer@cs.sunysb.edu>, Francois Bry <bry@ifi.lmu.de>
- Cc: public-rif-wg@w3.org
At 08:48 AM 2/9/2006 -0500, Michael Kifer wrote: > > > > Ed Barkmeyer wrote > > > > >The point is that a "business rule" taken out of an interpretation > context can > > >be highly ambiguous. > > > > > Right. But this "out-of-context" use is an extremely important issue. > > THe Web has been successfull to a largfge extent because it is based on > > making an "out-of-context" use possible. My strong conviction is that > > RIF should make such a use easy. > > > > Consider again my example: "every student with major in Computer Science > > must have a minor in Mathematics or in Physics". > >I believe that when people talk about disjunctive heads, they mean >deductive rules. Integrity constraint like the above are represented as >queries in LP and DBs. It is a query with an implication in the body, which >has a disjunction in the head (of that embedded implication). Lloyd-Topor >transforms it into constraints with no disjunction or implication. >So, this is not the kind of rules that Dieter meant to exclude, I believe. > >I think we have a consensus that we should not tackle disjunctions in the >heads of *deductive* rules in Phase 1. Perhaps not even in Phase 2. >However, we *should* design RIF in such a way that such extensions would >be possible. Thanks! Indeed I was trying to understand whether people want to have disjunction in integrity constrains or in ordinary rules. Unfortunately, the proposer were switching arguments from email to email. And indeed, answer set programming is an interesting paradigm for phase 3 or 4. ---------------------------------------------------------------- Dieter Fensel, http://www.deri.org/ Tel.: +43-512-5076485/8 Skype: dieterfensel
Received on Thursday, 9 February 2006 13:54:43 UTC