A characterization of Askey-Wilson polynomials

Please read abstract in the article.The research of the first author was supported by a Vice-Chancellor’s Postdoctoral Fellowship from the University of Pretoria. The research by the second author was partially supported by the National Research Foundation of South Africa under grant number 108763.http://www.ams.org/publications/journals/journalsframework/prochj2019Mathematics and Applied Mathematic