(define p (open-output-file "tinker10.log"))

(define (next-step x y a b c d counter)
        (penup)
        (setxy x y)
        (pendown)
        (forward 4)
        (cond ((and (< x 2) (< y 2))
        (cond ((< counter 300)
               (next-step (+ (* x x) (- 0 (* y y)) (* a x) (* b y)) 
                          (+ (* 2 x y) (* c x) (* d y))
                          a b c d (+ 1 counter)))))))

(define (go-next changer)
(cond ((< changer 0.52)
        (next-step -0.72 -0.64 0.9 0.6013 2 changer 1)
        (go-next (+ changer 0.001)))))

(go-next 0.48)