Artificial Intelligence and Soft Computing: Behavioral ... - Arteimi.info

3
Production
Systems
‘Production systems’ is one of the oldest techniques of knowledge
representation. A production system includes a knowledge base, represented
by production rules, a working memory to hold the matching patterns of data
that causes the rules to fire and an interpreter, also called the inference
engine, that decides which rule to fire, when more than one of them are
concurrently firable. On firing of a rule, either its new consequences are
added to the working memory or old and unnecessary consequences of
previously fired rules are dropped out from the working memory. The
addition to and deletion from working memory depends on the consequent
(then) part of the fired rule. Addition of new elements to the working memory
is required to maintain firing of the subsequent rules. The deletion of data
elements from the working memory, on the other hand, prevents a rule from
firing with the same set of data. This chapter provides a detailed account of
production systems, its architecture and relevance to state-space formulation
for problem solving.
3.1 Introduction
Knowledge in an Expert System can be represented in various ways. Some
the well-known techniques for representation of knowledge include