Simultaneous disturbance rejection and decoupling with stability: a structural approach

In this paper, it is shown that a static state feedback control law rejects the disturbance and simultaneously performs input-output decoupling, while insuring internal stability of the closed loop system, if and only it two integer equalities hold for the global undisturbed system and the row subsystems of the combined plant (where the disturbance is handled as a control input), namely in terms of their respective infinite and unstable contents (sums of the orders of the multiplicities of these singularities)