Abstract
We describe how Event-Condition-Action (ECA) rules can be combined with event algebras like SNOOP for specification of the event part, and process algebras like CCS for specification of the action part to obtain a powerful, declarative formalism that also covers intuitively procedural tasks in an appropriate way. Since these formalisms have a concise formal semantics, verification and other kinds of reasoning about such specifications are possible. Using a rulemarkupwith cleanly distinguished rule components allows for such a compositional approach. The approach is currently under implementation in the MARS (Modular Active Rules for the Semantic Web) Framework.