CONCUR 2004 START ConferenceManager    

Parameterised boolean equation systems (extended abstract)

Jan Friso Groote and Tim A.C. Willemse

Presented at Fifteenth International Conference on Concurrency Theory (CONCUR 2004), London, England, 31 August - 3 September, 2004


Boolean equation system are a useful tool for verifying formulas from modal mu-calculus on transition systems (see PhD thesis of Mader for an excellent treatment). We are interested in an extension of boolean equation systems with data. This allows to formulate and prove a substantially wider range of properties on much larger and even infinite state systems. In previous works it has been outlined how to transform a modal formula and a process, both containing data, to a so-called parameterised boolean equation system, or equation system for short. In this article we focus on techniques to solve such equation systems.

We introduce a new equivalence between equation systems, because existing equivalences are not compositional. We present techniques similar to Gauss elimination as outlined in [Mader] that allow to solve each equation system provided a single equation can be solved. We give several techniques for solving single equations, such as approximation (known), patterns (new) and invariants (new). Finally, we provide several small but illustrative examples of verifications of modal mu-calculus formulas on concrete processes to show the use of the techniques.

START Conference Manager (V2.47.4)