Model-checking for real-time systems specified in Lotos
- First Online:
- Cite this paper as:
- Rico N., v. Bochmann G., Cherkaoui O. (1993) Model-checking for real-time systems specified in Lotos. In: von Bochmann G., Probst D.K. (eds) Computer Aided Verification. CAV 1992. Lecture Notes in Computer Science, vol 663. Springer, Berlin, Heidelberg
This paper aims at describing and analyzing concurrent systems whose behavior is dependent on explicit time delays. The formal description technique Lotos [Loto 89] is extended with time intervals in the following way: actions in Lotos must occur at a time t within a given interval [tmin,tmax] relative to the previous action executed by the process. The syntax and semantics of Time Interval Lotos is given. The model is defined as a labelled transition systems with clocks associated with states and timing conditions associated with transitions. The labelled transition system derived corresponds to a timed graph model [Alur 90]. The logic TCTL (Computation Tree Logic with time) which allows quantitative operators in the formulas can be used to specify assertions. Model-checking is used to determine the truth of a TCTL-formula with respect to a labelled transition system derived from the Time Interval Lotos specification. We illustrate the approach by a simple example. We also present an alternative approach for verifying timing properties. A labelled transition system with time intervals is derived. This graph does not represent the precise evolution of the system in time. Each transition is labelled with an action and a time interval showing the range of possible time occurrences for the action.
Unable to display preview. Download preview PDF.