Higher Order Process-Algebraic Axiomatizations of Statecharts Variants

Axiomatizations are given for some prominent variants of the semantics of the statecharts formalism. The axiomatizations highlight the similarities and di erences amongst the semantics. In particular, all the semantics rely on the same notion of \microstep", but di erent notions of \step sequence". A process-algebraic approach is taken, and an executable variety of higher order logic is used, allowing test runs to be performed concerning the e ects of the semantics. It is shown that the higher order logic setting facilitates the addition of complex features not previously studied in process-algebraic approaches, including state-exiting transitions and history transitions. Other desirable features are also added, such as state name scoping.