- From: Jos de Bruijn <debruijn@inf.unibz.it>
- Date: Fri, 12 Dec 2008 18:47:48 +0100
- To: Sandro Hawke <sandro@w3.org>
- Cc: RIF WG <public-rif-wg@w3.org>
Quoting Sandro Hawke <sandro@w3.org>: > > > Talking about > http://www.w3.org/2005/rules/wiki/Disjunctive_Information_from_Negative_Guards_3 >> > who cares about this test case? Why is it important? >> >> it shows that you need to reason by cases, which is not usual in >> rule-based systems. > > Here's a simpler one, I think: > > Document( > Prefix(ex http://example.com/example#) > Prefix(pred http://www.w3.org/2007/rif-builtin-predicate#) > Group( > Forall ?x (ex:q(?x) :- > Or ( > External(pred:isNotInteger(?x)) > External(pred:isInteger(?x)) > ) > ) > ) > > entails: > ex:q(ex:a) Yes, this is also a good one. I think it nicely complements the test case Disjunctive_Information_from_Negative_Guards_3. Your test case shows how you need to do reasoning by case using the rule bodies, whereas Disjunctive_Information_from_Negative_Guards_3 show how you need to reason by case with the rule heads. Jos > > It's logically entailed, but neither a production rule system nor a > prolog-style system is going to figure that out. (The prolog one > might, by mistake, if it took ex:a as a prolog atom.) > > -- Sandro > >
Received on Friday, 12 December 2008 17:48:28 UTC