A recursive process is one in which objects are defined in terms of other objects of the same type. Using some sort of Recurrence Relation, the entire class of objects can then be built up from a few initial values and a small number of rules. The Fibonacci Numbers are most commonly defined recursively. Care, however, must be taken to avoid Self-Recursion, in which an object is defined in terms of itself, leading to an infinite nesting.

**References**

Buck, R. C. ``Mathematical Induction and Recursive Definitions.'' *Amer. Math. Monthly* **70**, 128-135, 1963.

Knuth, D. E. ``Textbook Examples of Recursion.'' In
*Artificial Intelligence and Mathematical Theory of Computation, Papers in Honor of John McCarthy*
(Ed. V. Lifschitz). Boston, MA: Academic Press, pp. 207-229, 1991.

Péter, R. *Rekursive Funktionen.* Budapest: Akad. Kiado, 1951.

© 1996-9

1999-05-25