On Mobility and Communication

                        Wenjie Du and Yuxin Deng


By imposing three semantic constraints on the pi-calculus equipped with
delayed input, we obtain a variant of the pi-calculus. We prove that Hennessy
and Riely's distributed pi-calculus can be encoded into this new model, 
satisfying a full abstraction theorem, which means that one-dimensional 
mobility can be characterized by communication. We also discuss the 
difficulties of expressing two-dimensional mobility, the mechanism 
used by ambient calculi.