Atomization of Alloy Constraints

Constraints in Alloy, a declarative modeling language, can be translated into Boolean logic and solved with a SAT solver. Atomization is a technique for improving the performance of Alloy analyses; it exploits typing relationships in an Alloy model and produces a semantically equivalent model that can be translated into Boolean form using fewer variables, hence creating a formula that can be solved more quickly. We give detailed experimental data on the performance of atomization on a number of Alloy models; in a majority of the cases, we found a sizable improvement in performance with atomization. We analyze atomization’s effect on SAT solving time and other components of execution time, and also examine the effects of heuristics that have been developed to improve atomization’s performance.