Algebraic State Transition Diagrams

This paper introduces a graphical notation called alge-braic state transition diagrams (ASTD), which allows for the combination of state transition diagrams using classical process algebra operators like sequence, iteration, parallel composition, quantified choice and quantified synchroniza-tion. It is inspired from automata, statecharts and process algebras. Hence, it combines the strength of all these no-tations: graphical representation, hierarchy, orthogonality, compositionality, abstraction. Quantification is one of the salient features of ASTDs, because it provides a powerful mechanism for modeling an arbitrary number of instances of an ASTD. A formal operational semantics is given. Our target application domain is the specification of information systems, but ASTDs are presented in a generic manner