The Inference Block

The previous chapters discuss simple rules and the operation of the backwardchain and forwardchain keywords. To write and process rules, you need one more construct-the inference block.

An inference block is written in a method and contains all code dealing with inferencing. It begins with the keyword INFER and finishes with the keyword END. Two things always occur in an inference block:

• Rules are posted
• A chaining command is issued (backwardchain or forwardchain)
• An inference block may contain more than one chaining command.

An inference block may contain other language statements, including method calls and regular if-then statements (not to be confused with the ifrule keyword used in rules).

A class may contain several inference blocks, which may be dynamically nested.