Using Model Checking to Automatically Find Retrieve Relations

Downward and upward simulations form a sound and jointly complete methodology for verifying relational data refinement in state-based specification languages such as Z and B. In previous work, we showed how both downward and upward simulation conditions can be discharged using a CTL model checker. The approach was implemented in the SAL tool suite. Given the retrieve relation, each of the simulation conditions can be proven fully automatically. It has been recognised, however, that finding retrieve relations is often very hard. In this paper, we show how it is feasible to use the SAL model checkers to also generate retrieve relations.