eld test&quot; of its accumulated contents.
If the knowledge base fails to serve any live inquiry in a satisfactory manner,
then there may be reason to reconsider some of its rules.

I will now detail how these principles of learning, transfer, and testing
apply to the &quot;Rainy Day&quot; example.

2.3.1  Learning

Rules in a knowledge base, as far as their effective content goes,
can be obtained by any mode of inference.  For example, a rule like

(Rule)   B =&gt; A,   &quot;just Before it rains, the Air