On Reduction Semantics for the Push and Pull Ambitent Calculus

Honda and Yoshida showed how to obtain a meaningful equivalence on processes in the asynchronous -calculus using equational theories identifying insensitive processes. We apply their approach to a dialect of Cardelli and Gordon’s Mobile Ambients. The version we propose here is the Push and Pull Ambient Calculus, where the operational semantics is no longer defined in terms of ambients entering and exiting other ambients, but in terms of being pulled and being pushed away by another ambient. Like the standard ambient calculus, this dialect has the computational power of the asynchronous -calculus. We contend that the new calculus allows a better modelling of certain security issues.