  = 0:  successful exit;
          &lt; 0:  if INFO = -i, the i-th argument had an illegal
                value;
          = 1:  if the matrix I - alpha*D*F is numerically singular.

</PRE>
<A name="Method"><B><FONT SIZE="+1">Method</FONT></B></A>
<PRE>
  The matrices of the closed-loop system have the expressions:

  Ac = A1 + beta*B1*K,      Bc = B1*G,
  Cc = H*(C1 + beta*D1*K),  Dc = H*D1*G,

  where

  A1 = A + alpha*B*F*E*C,   B1 = B + alpha*B*F*E*D,
  C1 = E*C,                 D1 = E*D,

  with E = (