Optimising the ProB model checker for B using partial order reduction

Abstract

Abstract Partial order reduction has been very successful at combatting the state explosion problem for lower-level formalisms, but has thus far made hardly any impact for model checking higher-level formalisms such as B, Z or TLA + . This paper attempts to remedy this issue in the context of Event-B, with its much more fine-grained events and thus increased potential for event-independence and partial order reduction. In this work, we provide a detailed description of a partial order reduction for explicit state model checking in ProB. The technique is evaluated on a variety of models. The implementation of the method is discussed, which is based on new constraint-based analyses. Further, we give a comprehensive description for elaborating the implementation into the LTL model checker of ProB for checking LTL − X formulae.