/B>
<PRE>
  INFO    INTEGER
          = 0:  successful exit;
          &lt; 0:  if INFO = -i, the i-th argument had an illegal
                value;
          = 1: if the matrix A22-g*I (see METHOD) is numerically
               singular.

</PRE>
<A name="Method"><B><FONT SIZE="+1">Method</FONT></B></A>
<PRE>
  Given the system (A,B,C,D), partition the system matrices as

         ( A11 A12 )        ( B1 )
     A = (         ) ,  B = (    ) ,  C = ( C1  C2 ),
         ( A21 A22 )        ( B2 )

  where A11