Bisimulation Through Probabilistic Testing

Abstract

We propose a language for testing concurrent processes and examine its strength in terms of the processes that are distinguished by a test. By using probabilistic transition systems as the underlying semantic model, we show how a testing algorithm with a probability arbitrary close to 1 can distinguish processes that are not bisimulation equivalent. We also show a similar result (in a slightly stronger form) for a new process relation called 2/3-bisimulation — lying strictly between that of simulation and bisimulation. Finally, the ultimately strength of the testing language is shown to identify an even stronger process relation, called probabilistic bisimulation.