Integrating ProB into the TLA Toolbox

Features. Animation is one of the most useful features of ProB that is not currently supported by the TLAtool chain. It allows a user to interact with the specification by discovering the statespace step by step and to evaluate expressions on the current state. Animation could be especially useful for newcomers to get familiar with TLA. Moreover, the ProB animator can be used to control a graphical visualization of a specification (top right view in Fig. 1). Apart from that, ProB is a model checker complementary to TLC. Experimental results comparing both model checkers can be found in [3]. Another useful feature of ProB is called constrained based model checking. In this mode of operation, ProB does not explore all reachable states starting from the initial state(s), but checks whether a single step of the next-state relation can result in an invariant violation