Correction and comment for the paper
T.H. Koornwinder, The structure relation for Askey-Wilson polynomials,
J. Comput. Appl. Math. 207 (2007), 214-226.

(last modified, September 30, 2021)

Correction:

On the left-hand side of (4.11) replace $(Lf)[z]$ by $(Lp_n)[z]$.


Comment:

The derivation of formula (2.6) with L given by (2.12) is for the
case of classical orthogonal polynomials essentially already contained
in formula (4) of the paper

D.V. Ho, J.W. Jayne and M.B. Sledd,
Recursively generated Sturm-Liouville polynomial systems,
Duke Math. J. 33 (1966), 131-140.

and for the case of Hahn class orthogonal polynomials in Theorem 1 of the
paper

W. Koepf and D. Schmersau,
On a structure formula for classical q-orthogonal polynomials,
J. Comput. Appl. Math. 136 (2001), 99-107.