Truly Concurrent Logic via In-Between Specification

In order to obtain a formalism for the specification of true concurrency in reactive systems, we modify the μ-calculus such that properties that are valid during the execution of an action can be expressed. The interpretation of this logic is based on transition systems that are used to model the ST-semantics. We show that this logic and step equivalence have an incomparable expressive power. Furthermore, we show that the logic characterizes the ST-bisimulation equivalence for finite process algebra expressions that do not contain synchronization mechanisms.