(define (time f)
(let ((start (current-jiffy)))
(f)
(/ (- (current-jiffy) start)
(jiffies-per-second))))
(define (tak x y z)
(if (> x y)
(tak (tak (- x 1) y z)
(tak (- y 1) z x)
(tak (- z 1) x y))
y))
(define (f)
(tak 12 6 0))
(write (time f))
(newline)