Set-oriented constructs for rule-based systems

Set-oriented constructs for forward chaining rule-based systems are presented. These constructs allow arbitrary amounts of data to be matched and changed within the execution of a single rule. Second-order tests on the data can be included in the match. The ability of a single rule to directly access all of the data to be manipulated eliminates the need for unwieldy control mechanisms and marking schemes. Adding this expressivity to rule-based languages enhances their value to expert system developers and their capabilities as database programming languages. Additionally, these set-oriented constructs provide a basis for more efficient implementations of rule-based systems, for both the traditional memory-based system and the emerging disk-based ones. The approach described has been implemented using an extended version of the Rete network algorithm