 For example, if "f" calls itself, that is direct recursion.If instead "f" calls "g" and then "g" calls "f," which in turn calls "g" again, from the point of view of "f" alone, "f" is indirectly recursing, while from the point of view of "g" alone, "g" is indirectly recursing, while from the point of view of both, "f" and "g" are mutually recursing on each other.Similarly a set of three or more functions that call each other can be called a set of mutually recursive functions.