Now we come to the last of universal models that we are going to analyse in this course and it is the p-calculus. A function that is discussed, that we discussed in l-calculus is essentially geared towards termination. A process on the other hand, is geared towards continuation. A process is something that if it stops, then it has a bug.
Now, we know that we could model in a functional language co-inductively processes using a datatype of streams; but, in fact, what happens is this kind of encoding might not bring to the fallgroundthe relevant aspects of processes.
So, indeed, a more direct axiomatic view might be convenient; and it is to introduce so called process algebras. And we know that there is a number multitude of these process algebras: among these there's the calculus of communicating systems, of Millner, the CSP of Hoare.