mal size of the DWORK
          array, returns this value as the first entry of the DWORK
          array, and no error message is issued by XERBLA.

  BWORK   LOGICAL array, dimension (N/2)

</PRE>
<B>Error Indicator</B>
<PRE>
  INFO    INTEGER
          = 0: succesful exit;
          &lt; 0: if INFO = -i, the i-th argument had an illegal value;
          = 1: periodic QZ iteration failed in the SLICOT Library
               routines MB04BD or MB04HD (QZ iteration did not
               converge or computa