x U   must be multiplied by the scaling factor
                     21
          contained in DWORK(4).

  LDU     INTEGER
          The leading dimension of array U.  LDU &gt;= MAX(1,2*N).

</PRE>
<B>Tolerances</B>
<PRE>
  TOL     DOUBLE PRECISION
          The tolerance to be used to test for near singularity of
          the original matrix pencil, specifically of the triangular
          M-by-M factor obtained during the reduction process. If
          the user sets TOL &gt; 0, then the given value of T