As discussed in Chapter 2, it is reasonable to model a good deal of human reasoning under certainty using logic. This model led to the development of rule-based systems that use the inference engines forward chaining and backward chaining. For example, it is reasonable to postulate that Mary the botanist has the following rule or item of knowledge stored in her personal data bank of knowledge:
|IF||stem is woody|
|THEN||type is tree.|
Furthermore, if Mary were determining the family of a particular plant, it is plausible that she would reason in a way similar to the decision tree in Figure 2.2, which is the equivalent of backward ...