CBS is a simple and natural CCS-like calculus where processes speak one at a time and are heard instantaneously by all others. Speech is autonomous, contention between speakers being resolved nondeterministically, but hearing only happens when someone else speaks. Observationally meaningful laws differ from those of CCS. The change from handshake communication in CCS to broadcast in CBS permits several advances. (1) Priority, which attaches only to autonomous actions, is simply added to CBS in contrast to CCS, where such actions are the result of communication. (2) A CBS simulator runs a process by returning a list of values it broadcasts. This permits a powerful combination, CBS with the host language. It yields several elegant algorithms. Only processes with a unique response to each input are needed in practice, so weak bisimulation is a congruence. (3) CBS subsystems are interfaced by translators; by mapping messages to silence, these can restrict hearing and hide speech. Reversi...

. [Pra91, Pra92] develop CBS, a CCS-like calculus [Mil89] where processes communicate by broadcasting values along a single channel. These values are hidden or restricted by translation to noise. This paper types CBS and restricts it to processes with a unique response to each input. Nondeterminism arises only if two processes in parallel both wish to transmit. These restrictions do not reduce the programming power of CBS. But strong and weak bisimulation can now be defined exactly as in CCS, yet capture observationally meaningful relations. Weak bisimulation is a congruence. This paper also shows how to program in CBS in a (lazy) ML framework. A simple CBS simulator is given, and a parallel implementation discussed. The simulator represents data evaluation, recursion and conditionals directly in Lazy ML. It implements an extended CBS with evaluation as well as communication transitions. [Pra91, Pra92] develop a CCS-like [Mil89] calculus of broadcasting systems, CBS. This paper continu...