Formal Characterization of HAAD

Abstract

We present here a formal characterization of non annotated action diagrams and develop a proof system for the language of Leaf Action Diagrams. We adopt a process algebra style “à la CCS” [25] in the presentation of the language, and provide structured operational semantics, in order to exploit the structural properties inherent in the action diagrams. Within this framework, Action Diagrams are algebraic terms constructed using a few operators and a set of atomic actions. Terms modeling Hierarchical Action Diagrams are built in two steps. First, basic terms corresponding to the leaf diagrams are built using prefixing, parallel composition and few timed constructs that capture the timing knowledge (Assume and Commit) of the action diagrams. We then define the hierarchical language by adding a set of hierarchical operators to the basic language.