Calculus of Finite Differences

There is more than mere coincidence in the fact that the recent rapid growth in the theory and application of mathematical statistics has been accompanied by a revival in interest in the Calculus of Finite Differences. The reason for this phenomena is clear: the student of mathematical statistics must now regard the finite calculus as just as important a tool and prerequisite as the infinitesimal calculus. To my mind, the progress that has been made to date in the development of the finite calculus has been marked and
stimulated by the appearence of four outstanding texts.