Now assume *W**e**=w**s**I, W**d**=I, W**1**=I, W**2**=w**t**I* and *P* is stable and has a stable inverse (I.e.,
minimum phase) and *K(s)=P**-1**(s)l(s)* such that *K(s)* is proper and the
closed-loop is stable. Then

and

Let the SVD of *P*(jw) be

with and where *m* is the dimension of *P*.

Then