Abstract. Appel is a general language for expressing policies in a variety of application domains with a clear separation between the core language and its specialisation for concrete domains. Policies can conflict, thus leading to undesired behaviour. We present a novel formal semantics for the Appel language based on ∆DSTL(x) (so far Appel only had an informal semantics). ∆DSTL(x) is an extension of temporal logic to deal with global applications: it includes modalities to localize properties to system components, an operator to deal with events, and temporal modalitiesà la Unity. A further contribution of the paper is the development of techniques based on the semantics to reason about conflicts.
The distributed state temporal logic of REF is an extension of Unity for formalising policies; it includes an operator to deal with events and modalities to localise properties of system components.
Logic-based detection of conflicts in APPEL policies
Massachusetts Institute of Technology
Computer Science