er, the resulting
  dimensions of the blocks are usually larger; this could make
  subsequent calculations less efficient.

  When SORT = 'C' or 'B', the procedure is similar to that for
  SORT = 'N' or 'S', respectively, but the blocks of A   and B
                                                      22      22
  whose eigenvalue(s) is (are) the closest to those of (A  , B  )
                                                         11   11
  (not to their mean) are selected and moved to the leading positi