AN ALGORITHM FOR COMPUTING THE MASK VALUE OF THE SUPREMAL NORMAL SUBLANGUAGE OF A LEGAL LANGUAGE

We consider the problem of finding the mask value of the supremal normal sublanguage L(R) of some given language L. We describe a straightforward algorithmic solution that can be applied to existing off-line procedures for determining the supremal controllable and normal sublanguage of L and that does not require an explicit calculation of L(R). This problem is fundamental because it is related to the supervisory control problem under partial observation. Our algorithm applies only to closed languages.