On the Asaithambi-Zuhe-Moore algorithm for computing the range of values

Asaithambi, Zuhe, and Moore (Computing 28, 225–237, 1982) presented an algorithm to find good upper and lower bounds on the range of values of a function of several variables on an n- dimensional rectangle. Unfortunately, the algorithm presented there contains some errors. In this paper, we point out these errors, show how they may be corrected, and suggest improvements of the algorithm.