   perturbed values were used to solve the equation;
          = 2:  if FACT = 'N' and DICO = 'C', but the matrix A is
                not stable (that is, one or more of the eigenvalues
                of A has a non-negative real part), or DICO = 'D',
                but the matrix A is not convergent (that is, one or
                more of the eigenvalues of A lies outside the unit
                circle); however, A will still have been factored
                and the eigenvalues of A returned in W;
 