Correct and Efficient Antichain Algorithms for Refinement Checking

The notion of refinement plays an important role in software engineering. It is the basis of a stepwise development methodology in which the correctness of a system can be established by proving, or computing, that a system refines its specification. Wang et al. describe algorithms based on antichains for efficiently deciding trace refinement, stable failures refinement and failures-divergences refinement. We identify several issues pertaining to the soundness and performance in these algorithms and propose new, correct, antichain-based algorithms. Using a number of experiments we show that our algorithms outperform the original ones in terms of running time and memory usage. Furthermore, we show that additional run time improvements can be obtained by applying divergence-preserving branching bisimulation minimisation

Correct and Efficient Antichain Algorithms for Refinement Checking

The notion of refinement plays an important role in software engineering. It is the basis of a stepwise development methodology in which the correctness of a system can be established by proving, or computing, that a system refines its specification. Wang et al. describe algorithms based on antichains for efficiently deciding trace refinement, stable failures refinement and failures-divergences refinement. We identify several issues pertaining to the soundness and performance in these algorithms and propose new, correct, antichain-based algorithms. Using a number of experiments we show that our algorithms outperform the original ones in terms of running time and memory usage. Furthermore, we show that additional run time improvements can be obtained by applying divergence-preserving branching bisimulation minimisation

Modelling and analysing software in mCRL2

Model checking is an effective way to design correct software.Making behavioural models of software, formulating correctness properties using modal formulas, and verifying these using finite state analysis techniques, is a very efficient way to obtain the required insight in the software. We illustrate this on four common but tricky examples

Partial-order reduction for parity games with an application on parameterised Boolean Equation Systems (Technical Report)

Partial-order reduction (POR) is a well-established technique to combat the problem of state-space explosion. Most approaches in literature focus on Kripke structures or labelled transition systems and preserve a form of stutter/weak trace equivalence or weak bisimulation. Therefore, they are at best applicable when checking weak modal mucalculus. We propose to apply POR on parity games, which can encode the combination of a transition system and a temporal property. Our technique allows one to apply POR in the setting of mu-calculus model checking. We show with an example that the reduction achieved on parity games can be significantly larger. Furthermore, we identify and repair an issue where stubborn sets do not preserve stutter equivalence

Exact analysis for basic cyclic executives

The academic interest in cyclic executives for multitasking in hard real-time systems decreased significantly during the past decades. Moreover, cyclic executives are hardly addressed in contemporary text books, if at all. Cyclic executives are still in use, however, and there is therefore a need for analysis techniques for these executives.In this document, we present exact analysis for basic cyclic executives scheduling a given sequence of independent hard real-time polling tasks in single-processor systems. Unlike existing approaches, which typically take periodic tasks as a starting point for cyclic executives and focus on schedulability of tasks, we take the schedulability of the system as a starting point, i.e. whether or not the system meets its deadlines. In particular, we do not assume periods and deadlines for tasks

Correct and efficient antichain algorithms for refinement checking

\u3cp\u3eRefinement checking plays an important role in system verification. This means that the correctness of the system is established by showing a refinement relation between two models; one for the implementation and one for the specification. In [21], Wang et al. describe an algorithm based on antichains for efficiently deciding stable failures refinement and failures-divergences refinement. We identify several issues pertaining to the correctness and performance in these algorithms and propose new, correct, antichain-based algorithms. Using a number of experiments we show that our algorithms outperform the original ones in terms of running time and memory usage.\u3c/p\u3

Correct and efficient antichain algorithms for refinement checking

Refinement checking plays an important role in system verification. This means that the correctness of the system is established by showing a refinement relation between two models; one for the implementation and one for the specification. In More Anti-chain Based Refinement Checking , Wang et al. describe an algorithm based on antichains for efficiently deciding stable failures refinement and failures-divergences refinement. We identify several issues pertaining to the soundness and performance in these algorithms and propose new, correct, antichain-based algorithms. Using a number of experiments we show that our algorithms outperform the original ones in terms of running time and memory usage. Furthermore, we show that applying divergence-preserving branching bisimulation reduction results in additional run time improvements

Correct and efficient antichain algorithms for refinement checking

The notion of refinement plays an important role in software engineering. It is the basis of a stepwise development methodology in which the correctness of a system can be established by proving, or computing, that a system refines its specification. Wang et al. describe algorithms based on antichains for efficiently deciding trace refinement, stable failures refinement and failures-divergences refinement. We identify several issues pertaining to the soundness and performance in these algorithms and propose new, correct, antichain-based algorithms. Using a number of experiments we show that our algorithms outperform the original ones in terms of running time and memory usage. Furthermore, we show that additional run time improvements can be obtained by applying divergence-preserving branching bisimulation minimisation