Comparing locality and causality based equivalences (Q1342503)

For Milner's CCS several noninterleaving semantics have been proposed among which causal bisimulations [\textit{P. Darondeau} and \textit{P. Degano}, Lect. Notes Comput. Sci. 452, 239-245 (1990; Zbl 0733.68027)] and location equivalence [\textit{G. Boudol}, \textit{I. Castellani}, \textit{M. Hennessy} and \textit{A. Kiehn}, Theor. Comput. Sci. 114, No. 1, 31-61 (1993; Zbl 0783.68072)] play a central role. To unify these two approaches this paper introduces a new transition system based on local and global causes. Bisimulation equivalence is parameterized by a function \(f\) which evaluates the information on causes provided by the transitions. Appropriate instantiations of \(f\) yield characterizations of causal bisimulations and location equivalence.