Back to slide -- Keyboard shortcut: 'u'  previous -- Keyboard shortcut: 'p'  next -- Keyboard shortcut: 'n'          fac-ok-2.scm - Equivalent to the program above - notice the use of assignment.Lecture 2 - slide 10 : 35
Program 4

(let ((fac #f))
  (set! fac (lambda (n)
              (if (= n 0) 1 (* n (fac (- n 1))))))
  (fac 5))

; OK. 120