Equivalences on observable processes

The finest observable and implementable equivalence on concurrent processes is sought as part of a larger program to develop a theory of observable processes where semantics of processes are based on locally and finitely observable process behavior and all process constructs are allowed, provided their operational meaning is defined by realistically implementable transition rules. The structure of transition rules is examined, and several conditions that all realistically implementable rules should satisfy are proposed. It is shown that the ISOS contexts capture exactly the observable behavior of processes. This leads to the result that copy plus refusal equivalence is the finest implementable equivalence