Lawrence Terrill on "The Rete Algorithm",

with questions and answers fielded by Dr. Charles Forgy, author of the Rete Algorithm.

It is our honor to not only have one of our finest speakers and most important topics, but the presence of Dr. Charles Forgy himself to answer questions. Please do not miss this opportunity to hear directly from one of the most influential and creative minds in AI today.

The Rete Algorithm was written in it's first incarnation almost 30 years ago, and has been the backbone of most serious production rules engine for decades.  The Rete Algorithm was written in 1979 for Dr. Forgy's Ph.D. thesis and, since it gave existing rulebased engine a 3000-to-1 speed increase, according to some text books made the commercialization of rulebased systems possible.  It has been the central part of 90% of forward-chaining rulebased systems and, in one form or another, is the essential part of ALL of the commercial BRMS engines today.

Editor's Note:

Lawrence Terrill is one of our finest speakers to date, and if 
you haven't heard him speak on rules you may have missed one of
the clearest, most easy to understand speakers on rules. He has a
knack for making complex things understandable, and this has 
helped many of us grasp aspects of how rules work that were 
previously beyond our grasp.

About the presentation:

This presentation is intended for rule engine novices with only a rudimentary understanding of rule evaluation and execution at the level of my previous presentation.

The goal is provide a basic understanding of how the process of repeated rule evaluation with each change to WM is actually very efficient when using the Rete algorithm, a somewhat counter-intuitive outcome. This is an explanation through example. A simple three-rule example is presented and the representative Rete network reviewed. Examples of behavior when adding objects to WM and the resulting updates to the network and the agenda are presented.

The presentation, An Introduction To The Rete Algorithm, is 18 slides and will thus be brief enough to allow plenty of time for Questions and Answers.

Also attached is the source code (java code and rules) for the example in the presentation. The example was executed using Drools V4.0.7, but should work with any current version of Drools.

Both, the presenation and the source code, are Copyright, EBDX.COM, LLC 2008 and are licensed for use by the Dallas Rules Group under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

About the Presenter:

Lawrence Terrill presented one of our last month's presentations and wlll be presenting again at October Rules Fest in Addison.

His bio is posted here, alphabetically under Lawrence Terrill.

About Dr. Charles Forgy

Perhaps the best place to read about Dr. Forgy is on wikipedia. Noted scientist, considered by many as the father of rules based systems, he is a prominent figure in AI today and has been for decades.