Coupled similarity is a notion of equivalence for systems with internal actions. It has outstanding applications in contexts where internal choices must transparently be distributed in time or space, for example, in process calculi encodings or in action refinements. No tractable algorithms for the computation of coupled similarity have been proposed up to now.

The poster gives an intuition for coupled similarity, describes our game characterization and explains how we use the game to compute coupled similarity relations in cubic time. It also sketches why deciding the coupled simulation preorder is at least as hard as deciding the weak simulation preorder.