Components of ES-1

Today we continue our talk on ES components.
(a) Knowledge based : The knowledge base contains both facts that describe the problem area and knowledge representation techniques that describe how the facts fits together in a logical manner. The term problem domain is used to describe the problem area. The popular knowledge representation techniques are rules and networks of rules.

The rules in the knowledge base are usually coded in the form. IF X THEN Y, where X is a condition, Y is an action to be taken if the condition is true. All the rules contained in an expert system are called the rule set.

The rules of a rule set are not physically linked, but their logical relationships can be established.

(b) Inference engine : The inference engine is the portion of the expert system that performs reasoning by using the contents of the knowledge base in a particular sequence. During the consultation, the inference engine examines the rules of the knowledge base one at a time, and when a rule’s condition is true, specified action is taken. In expert system terminology, the rule is fired when the action is taken.