- From: Sandro Hawke <sandro@w3.org>
- Date: Fri, 12 Dec 2008 12:26:31 -0500
- To: Jos de Bruijn <debruijn@inf.unibz.it>
- cc: RIF WG <public-rif-wg@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)
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 17:27:11 UTC