rule
From Glossary of Meteorology
A law or regulation that governs behavior, actions, or operations.
In rule-based systems, only those rules with true antecedents are used. For example, a rule that begins "IF the temperature is less than 0°C . . . " is ignored whenever the measured temperature is 0°C or higher.
See IF–THEN rule, production rule, antecedent, consequent.