Adaptive Symmetry Reduction

Symmetry reduction is a technique to counter state explosion for systems of regular structure. It relies on idealistic assumptions about indistinguishable components, which in practice may only be similar. In this paper we present a generalized algebraic approach to symmetry reduction for exploring a structure without any prior knowledge about its global symmetry. The more behavior is shared among the components, the more compression takes effect. Our idea is to annotate each encountered state with information about how symmetry is violated along the path leading to it. Previous solutions only allow specific types of asymmetry, such as up to bisimilarity, or seem to incur large overhead before or during the verification run. In contrast, our method appeals through its balance between generality and simplicity. We include analytic and experimental results to document its efficiency.