[plt-scheme] Scheme exercise(image.ss)

I came up with this

(define turn-off-red (lambda(traffic-light)
                   (overlay/xy (overlay/xy  LIGHT-FRAME 0 0 traffic-light) 0
(- OFFSET) (circle RADIUS 'solid 'white)) ))

(turn-off-red (overlay/xy (overlay/xy (overlay/xy LIGHT-FRAME 0 OFFSET GREEN
)
                          0 0 (circle RADIUS 'outline 'white))
              0 (- OFFSET) RED ))
(define traffic-light (overlay/xy (overlay/xy (overlay/xy LIGHT-FRAME 0
OFFSET GREEN )
                          0 0 (circle RADIUS 'outline 'white))
              0 (- OFFSET) RED ))

traffic-light

(turn-off-red ALL-THREE-ON)

ALL-THREE-ON

I think i got this now.

Aditya
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