ANALYSIS OF DATABASE PRODUCTION RULES BY PROCESS ALGEBRA

The purpose of this research is to analyze production rules with coupl ing modes in active databases and to exploit an assistant system for r ule programming. Each production rule is a specification including an event, a condition, and an action. The action is automatically execute d whenever the event occurs and the condition is satisfied. Coupling m odes are useful to control execution order of transactions. For exampl e, a transaction for consistency check should be executed after transa ctions for update. An active database, which is a database with produc tion rules, can spontaneously update database states and check their c onsistency Production rules provide a powerful mechanism for knowledge -bases. However it is very difficult in general to predict how a set o f production rules will behave because of cascading rule triggers, con currency, and so on. We are attempting to adopt a process algebra as a basic tool to analyze production rules. In order to describe and anal yze concurrent and communicating systems, process algebras such as CCS , CSP, ACP, and pi-calculus, are well known. However there are some di fficulties to apply existing process algebras to analysis of productio n rules in growing process trees by process creation. In this paper we propose a process algebra named CCSPR (a Calculus of Communicating Sy stems with Production Rules), which is an extension of CCS. An advanta ge of CCSPR is to syntactically describe growing process trees. Theref ore, production rules can be appropriately analyzed in CCSPR. After gi ving definitions and properties of CCSPR, we show an example of analys is of production rules in CCSPR.