Co-induction Characterization of Branching Bisimulation with Explicit Divergence∗

Branching bisimulation with explicit divergence, introduced by van Glabbeek and Weijland, is an important relation between processes. It is the weakest equivalence relation which is a branching bisimulation and at the same time divergence preserving. Like branching bisimulation, it has two major characterizations in the literature: a relational characterization and a coloured trace characterization. Unlike branching bisimulation, the two characterizations are not directly based on the powerful tool of co-induction. In this paper we propose a coloured trace characterization and a relational characterization, both based on co-induction. The new characterizations can benefit not only theoretical development, but also verification practice. 1998 ACM Subject Classification F.1.2