B2SAT: A Bare-Metal Reduction of B to SAT

Abstract

We present a new SAT backend for the B-Method to enable new applications of formal methods. The new backend interleaves low-level SAT solving with high-level constraint solving. It provides a “bare metal” access to SAT solving, while pre- and post-calculations can be done in the full B language, with access to higher-order or even infinite data values. The backend is integrated into ProB, not as a general purpose backend, but as a dedicated backend for solving hard constraint satisfaction and optimisation problems on complex data. In the article we present the approach, its origin in the proof of Cook’s theorem, and illustrate and evaluate it on a few novel applications of formal methods, ranging from biology to railway applications.