w.r.t. the statement below, [Don't think there's such a thing as "The Refraction Principle;" Jess has a particular behavior w.r.t. refraction, and other such behaviors have been proposed.]
Hmmm... This is something that I had not realized until now. However, section 2.8.1.3 of the Jess manual explains that there are two available conflict resolution strategies, basically LIFO and FIFO. Refraction, MEA and/or LEX are not discussed. Only breadth and depth strategies, along with salience (sometimes called priority in other systems) are discussed. However, most of the AI books at my disposal (and most commercial inference engines) implement either LEX (Lexical) or MEA (Means Ends Analysis) conflict resolution strategies. Most of them, with one notable exception, use MEA. If anyone want a listing of those books I would be happy to provide them. Both MEA and LEX have as their first item on the conflict resolution table the refraction principle, in that a rule (where a rule = logic+data) that has fired is removed from the agenda table and never returned. This seems to be a basic principle even in such older systems as Expert (a backward-chaining system from Neuron Data) as well as the newer incarnations such as OPSJ, JRules and Blaze Advisor. I know it was the first principle for all of the OPS systems from which our present-day engines seem to have been derived. So. My question is this: Considering that most inference engines do have refraction as the first item on the conflict resolution, is there a reason that the conflict resolution in Jess does NOT include refraction as the first principle? Or at all? I would say "all other inference engines" but I'm not intimately familiar with all of them - but all of the ones with which I do have experience use refraction as the first item on the conflict resolution system. One last thing: I took the survey indicated without reading the line below that says (or seems to indicate) that "per slot activation" is the same thing as "refraction" - Maybe I'm dense (Shut up Richard! You too Joe!) but I can't see the relationship between "per slot activation" and refraction as a means of conflict resolution. SDG jco James C. Owen Senior Knowledgebase Consultant 6314 Kelly Circle Garland, TX 75044 972.530.2895 214.684.5272 (cell) -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, June 16, 2003 11:08 AM To: [EMAIL PROTECTED] Subject: Re: JESS: Refraction I think Emmanuel Bonnet wrote: > Hi, > It seems that the refraction principle is not implemented yet in Jess. > I have seen it as a Proposed Feature in the archives > ( JESS: Proposed feature , 6 Jan 2003). Don't think there's such a thing as "The Refraction Principle;" Jess has a particular behavior w.r.t. refraction, and other such behaviors have been proposed. > > Does anybody knows : > . if it will be implemented in the near future ? Take the Jess Development Roadmap survey (see link on home page at http://herzberg.ca.sandia.gov/jess). The feature you're interested in is called "per-slot activations" in that survey. > . how I can "simulate" that behavior in the current Jess Version ? > You can't, really. > Regards, > Emmanuel > --------------------------------------------------------- Ernest Friedman-Hill Distributed Systems Research Phone: (925) 294-2154 Sandia National Labs FAX: (925) 294-2234 PO Box 969, MS 9012 [EMAIL PROTECTED] Livermore, CA 94550 http://herzberg.ca.sandia.gov -------------------------------------------------------------------- To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED] -------------------------------------------------------------------- -------------------------------------------------------------------- To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED] --------------------------------------------------------------------
