- From: Hassan Aït-Kaci <hak@ilog.com>
- Date: Wed, 08 Mar 2006 14:58:40 +0100
- To: Francois Bry <bry@ifi.lmu.de>
- CC: "Peter F. Patel-Schneider" <pfps@inf.unibz.it>, public-rif-wg@w3.org
Francois Bry wrote: > Peter F. Patel-Schneider wrote: > >>I don't understand which universe I've fallen into here. >> >>In my universe, production rule systems derived from OPS5. >> >>In my universe, OPS5 allowed rules like >> (p (parent ^parent <x> ^child <y>) >> (ancestor ^ancestor <y> ^descendant <z>) >> --> >> (make ancestor ^ancestor <x> ^descendant <z>)) >> >>In my universe, this was a recursive rule. >> >>What is different in this universe? >> > > My understanding is that Hassan - riogthly - pointed out that using a > production rule like the above (and its evaluator), one can implements a > recurrsive deduction rule stating that parents of ancestors are > themselves ancestors. > > Thus, the situation is like implementing the evaluation of a recursive > deduction rule using a while-block in an imperative programme: this > programme is not recursive even though it uimplements something which is > recursive. > > Hassan, did I got your point? You did. > Francois -hak -- Hassan Aït-Kaci ILOG, Inc. - Product Division R&D tel/fax: +1 (604) 930-5603 - email: hak @ ilog . com
Received on Wednesday, 8 March 2006 13:58:11 UTC