(defun fit (x)
  (abs (- (+ (* 2 x) 10)
	  (+ (* -5 x) 9))))

(defun experiment (&optional 
		   out
		   (max       100)
		   (min       -100)
		   (best      (fit max))
		   (max-lives 9)
		   (lives      max-lives))
  (print `(,min ,max))
  (if (zerop lives)
      (values out best)
  (let* ((guess (+ min (* (randf 1) (- max min))))
	 (score (fit guess)))
    (if (< score best)
	(let ((left  (- max guess))
	      (right (- guess min)))
	  (if (< left right)
	      (setf max (/ (+ max guess) 2))
	      (setf min (/ (+ min guess) 2)))
	  (experiment guess max min score max-lives max-lives))
	(experiment   out   max min best  max-lives (1- lives))))))