(define tolerance 0.00001)
(define (fixed-point f first-guess) 
  (define (close-enough? v1 v2) 
    (< (abs (- v1 v2)) tolerance)) 
  (define (try guess iteration) 
    (display iteration) 
    (display " : ") 
    (display guess) 
    (newline) 
    (let ((next (f guess))) 
         (if (close-enough? guess next) 
             next 
             (try next (+ iteration 1))))) 
  (try first-guess 1))