A Lisp Example: Recursive Factorial Function
One classic example is calculating a factorial. In Lisp, the factorial function can be defined recursively as follows:
(defun factorial (n) (if (<= n 1)
1
(* n (factorial (- n 1)))))
In this definition, if n is 1 or less (the base case), the function returns 1. Otherwise, it multiplies n by the factorial of (n-1), further breaking the problem into a simpler one until reaching the base case.