I think that these examples have clearly illustrated the expressive power of the p-calculus as far as describing concurrent processes. But indeed this is a universal model of computation where, as I said, the binding, the building block is communication within processes. And, in fact, one can show how to encode various data types in the p-calculus going through the natural numbers, pairs and all sorts of datatypes belonging to those binding algebras that we have described earlier, much as we did in the l-calculus.
Of course here the flavour is much more operational. What is surprising is that in this simple formalism we can represent also higher order a process algebras and functions.
