         = 3:  if FACT = 'F' and DICO = 'C', but the Schur factor S
                supplied in the array A is not stable (that is, one
                or more of the eigenvalues of S has a non-negative
                real part), or DICO = 'D', but the Schur factor S
                supplied in the array A is not convergent (that is,
                one or more of the eigenvalues of S lies outside the
                unit circle); the eigenvalues of A are still
                returned in W;
          = 6: