Production systems P.J. Drongowski 12/16/83 A production system is a collection of rules, a scratchpad memory and a directory of named objects (variables.) The rules have the two part form: situation -> action . When the "situation" is detected, the action part will be executed. The scratchpad provides a place where conditions or assertions can be temporarily recorded. The scratchpad is a list which is searched from head to tail. Assertions may be appended or removed from either end of the list. The current state of the scratchpad can affect the selection of a production for evaluation. The variables are named objects which retain values over a long period of time. Two operators may be applied to a variable: >var In a situation, var will match any value. The value will be stored in var.