On the existence of finite-state supervisors under partial observations

We consider discrete-event systems under partial observations. We show the equivalence of the (M, /spl Sigma//sub c/, L(G))-observability of a control specification and the (M, /spl Sigma//sub c/, /spl Sigma/*)-observability of its corresponding augmented language. We derive necessary and sufficient conditions for the existence of finite-state supervisors under partial observations.