er
          should avoid naively computing the ratio.
          If A and B are obtained from general matrices using ZGGES,
          ALPHA will be always less than and usually comparable with
          norm(A) in magnitude, and BETA always less than and
          usually comparable with norm(B).

</PRE>
<B>Tolerances</B>
<PRE>
  TOL     DOUBLE PRECISION
          If SORT = 'S' or 'B', the tolerance to be used in the
          ordering of the diagonal elements of the upper triangular
          matrix pair.
