Decentralised control of concurrent discrete-event systems with non-prefix closed local specifications

A problem of decentralised control of concurrent discrete-event systems is formulated. Two subsystems with shared events are considered. Specifications are given locally on the subsystems. The problem is to find a set of `structural´ conditions on the synchronisation between the two subsystems such that, for a set of local specifications, local syntheses and controls achieve the same behaviour as that of a global `optimal´ design for the overall specification, and control in one subsystem does not cause blocking in the other subsystem. Sufficient conditions are obtained. An example is provided for illustration