  A. Rosenfeld introduced the notion of a digitally continuous function between
digital images, and showed that although digital images need not have fixed
point properties analogous to those of the Euclidean spaces modeled by the
images, there often are approximate fixed point properties of such images. In
the current paper, we obtain additional results concerning fixed points and
approximate fixed points of digitally continuous functions. Among these are
several results concerning the relationship between universal functions and the
approximate fixed point property (AFPP).
