Timed and Hybrid Statecharts and their Textual Representation

. A structured operational semantics is presented for Timed and Hybrid Statecharts, which are generalizations of the visual specification language of Statecharts intended to model real-time and hybrid systems. In order to study some of the basic features of Statecharts and the extensions necessary to treat real-time and continuous behaviors without being distracted by the graphical representation, we introduce a concurrent real-time language that can be viewed as a textual representation of Statecharts. The language contains statements for delays, preemption, and timeouts. A structured operational semantics of the language and an illustrative example of its use for specification are presented. Extensions to the specification of hybrid systems are obtained by allowing a differential equation as a statement of the extended language. Structured operational semantics is also given for the hybrid version. The same extensions are then applied to the visual Statechart language, a..