CLIPS provides support for the modular development and execution of knowledge bases with the defmodule construct. CLIPS modules allow a set of constructs to be grouped together such that explicit control can be maintained over restricting the access of the constructs by other modules. This type of control is similar to global and local scoping used in languages such as C or Ada (note, however, that the global scoping used by CLIPS is strictly hierarchical and in one direction onlyóif module A can see constructs from module B, then it is not possible for module B to see any of module Aís constructs). By restricting access to deftemplate and defclass constructs, modules can function as blackboards, permitting only certain facts and instances to be seen by other modules. Modules are also used by rules to provide execution control.

10.1 DEFINING MODULES