h the new definitions of the

  blocks A  , A  , B  , and B  . After successful transformation
          11   22   11       22
  matrices X and Y have been obtained, they postmultiply the current
  transformation matrices (if JOBX = 'U' and/or JOBY = 'U') and the
  whole procedure is repeated for the new blocks A   and B  .
                                                  22      22

  When SORT = 'S', the diagonal elements of the generalized Schur
  form are reordered before each step of the reduction, so