- From: Dave Reynolds <der@hplb.hpl.hp.com>
- Date: Tue, 01 Jul 2008 14:42:01 +0100
- To: Mark Proctor <mproctor@redhat.com>
- CC: "Boley, Harold" <Harold.Boley@nrc-cnrc.gc.ca>, Gary Hallmark <gary.hallmark@oracle.com>, Christian de Sainte Marie <csma@ilog.fr>, RIF WG <public-rif-wg@w3.org>
Mark Proctor wrote: > > Dave Reynolds wrote: >> >> Boley, Harold wrote: >>> Production Rule languages such as the widely used CLIPS >>> (http://en.wikipedia.org/wiki/CLIPS) employ predicates >>> like car_problem with named arguments. >> >> I wasn't talking about named arguments in general but the specific >> case of "named argument uniterms with the semantics as defined in BLD" >> which is what I took the term "NAU" to stand for. >> >>> CLIPS (Wikipedia rule1 is a "pure production rule"): >>> >>> (deffacts trouble_shooting >>> (car_problem (name ignition_key) (status on)) >>> (car_problem (name engine) (status wont_start)) >>> (car_problem (name headlights) (status work)) >>> ) >> >> In CLIPS those are "unordered facts" (or deftemplate facts) and I >> believe you can partially match against them. For example you could >> also have a rule: >> >> (defrule rule1 >> (car_problem (status wont_start)) >> => >> (assert (car_problem (name suspectedStarter)) >> ) >> >> and it would still match those facts even though some arguments are >> missing. > yes this is correct. Named arguments on a pattern is a subset of the > available fields on the fact. Thanks. So this semantics is not directly compatible with the BLD notion of NAU. >> Thus I believe the CLIPS representation corresponds to more closely >> frames in RIF not to NAUs. I would certainly include Frames in core. > I still dislike that Frames insist on an OID, would be happier if that > could be dropped. Whole point with a pattern is that it's not pointing > to a specific instance. I understand that this can be hidden as an > implementation detail, I still think it's a cludge. With a pattern you would have a variable in the OID slot if you aren't trying to point to a specific instance. Cheers, Dave -- Hewlett-Packard Limited Registered Office: Cain Road, Bracknell, Berks RG12 1HN Registered No: 690597 England
Received on Tuesday, 1 July 2008 13:43:51 UTC