Z       (input/output) DOUBLE PRECISION array, dimension (LDZ,*)
          On entry, if JOBZ = 'U', then the leading N-by-N part of
          this array must contain a given matrix Z (e.g. from a
          previous call to another SLICOT routine), and on exit, the
          leading N-by-N part of this array contains the product of
          the input matrix Z and the column transformation matrix
          used to transform the columns of matrices A and E.
          On exit, if JOBZ = 'I', then the leading N