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8.4.  Recursion

First we discuss recursive definitions next. For example, if x is a person, then by definition, all the following persons are descendants of x.

1.   All children of x are descendants of x.
2.   If y is a child of x, then all descendants of y are
     descendants of x.
3.   Nobody else is a desendant of x.

In a recursive definition one distinguishes between a base rule and a recursive rule. The base rules of a recursive definition describes the term to be defined directly. The recursice rule contains the term to be defined in its own defintion.


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Last modified: 27/July/98 (12:14)