, 1979.

</PRE>
<A name="Numerical Aspects"><B><FONT SIZE="+1">Numerical Aspects</FONT></B></A>
<PRE>                                         2         2
  The algorithm requires approximately 5M N + 0.5MN  operations in
                         2         2
  the worst case and 2.5M N + 0.5MN  operations in the best case
  (where M is the order of the matrix in Hessenberg form and N is
  the order of the matrix in Schur form) and is mixed stable (see
  [1]).

</PRE>

<A name="Comments"><B><FONT SIZE="+1">Fu