Discrete semi-classical orthogonal polynomials

Orthogonal polynomials associated with Delta(omega)-semi-classical function als will be studied as a generalization of the Delta(omega)-classical funct ionals. The concept of class and a criterion for determining it will be giv en. The Delta(omega)-difference equation that the corresponding formal Stie ltjes series satisfies is obtained. The quasi-orthogonality property satisf ied by the Delta(omega)-differences of these polynomials is analyzed. Two s tructure relations as well as a quadratic relation are obtained. The second order difference equation is determined.