imal size of the
          ZWORK array, returns this value as the first entry of
          the ZWORK array, and no error message related to LZWORK
          is issued by XERBLA.

</PRE>
<B>Error Indicator</B>
<PRE>
  INFO    INTEGER
          = 0:  successful exit;
          &lt; 0:  if INFO = -i, the i-th argument had an illegal
                value.

</PRE>
<A name="Method"><B><FONT SIZE="+1">Method</FONT></B></A>
<PRE>
  The routine extracts from the system matrix of a state-space
  system (A,B,C,D) a r