“…Ronveaux et al 47,48] for classical and semiclassical orthogonal polynomials and Lewanowicz 30,34] for classical orthogonal polynomials have proposed alternative, simpler techniques of the same type although they require the knowledge of not only the recurrence relation but also the di erential-di erence relation or/and the second-order di erence equation, respectively, satis ed by the polynomials of the orthogonal set of the expansion problem in consideration. See also 5,11,23,31,45,46] for further description and applications of this method in the discrete case, and 19,32] in the continuous case as well as 3,33] for the q-discrete orthogonality. Koepf and Schmersau 25] has proposed a computer-algebra-based method which, starting from the second order di erence hypergeometric equation, produces by symbolic means and in a recurrent way the expansion coe cients of the classical discrete orthogonal hypergeometric polynomials (CDOHP) in terms of the falling factorial polynomials (already obtained analytically by Lesky 28]; see also 41], 42]) as well as the expansion coe cients of its corresponding inverse problem.…”