(define factorial-counter 0)

; factorial-count! : natnum -> natnum
; Effect: Increments factorial-counter once.
; Purpose: Returns the factorial of the given number.
(define (factorial-count! n)
  (local [(define (factorial n)
	    (cond
	      [(zero? n) 1]
	      [else      (* n (factorial (sub1 n)))]))]
    (begin
      (set! factorial-count (add1 factorial-count))
      (factorial n))))