Note for others: this is a variant of the original Good Regulator theorem. In particular, it assumes that the regulator R has perfect information about system state S, which is why I1 is able to be a deterministic function of I2.
Note for others: this is a variant of the original Good Regulator theorem. In particular, it assumes that the regulator R has perfect information about system state S, which is why I1 is able to be a deterministic function of I2.