There are tasks below please help me with these tasks (You need to use drracket program)

;visual constants (define R 50) (define W (* 2 R)) (define D (* 6 R)) (define ES (empty-scene W D)) (define FRAME (rectangle W D "outline" "black"))

(define REDL (place-image (overlay/xy (overlay/xy (overlay/xy FRAME 0 (* -2 R) (circle R "solid" "red")) 0 0 (circle R "outline" "yellow")) 0 (* 2 R) (circle R "outline" "green")) (/ W 2) (/ D 2) ES))

(define YELLOWL (place-image (overlay/xy (overlay/xy (overlay/xy FRAME 0 (* -2 R) (circle R "outline" "red")) 0 0 (circle R "solid" "yellow")) 0 (* 2 R) (circle R "outline" "green")) (/ W 2) (/ D 2) ES))

(define GREENL (place-image (overlay/xy (overlay/xy (overlay/xy FRAME 0 (* -2 R) (circle R "outline" "red")) 0 0 (circle R "outline" "yellow")) 0 (* 2 R) (circle R "solid" "green")) (/ W 2) (/ D 2) ES))

;TrafficLight (TL) is one of ; - "red" ; - "yellow" ; - "green" ; interp. each string above represents a corresponding traffic light.

(define-struct NTL (Light Timer)) ; NTL is a structure like ; (make-NTL String Number) ; Light is TL ; Timer is a Number represents time passed so far for the current light

;Time for each color (define RT 9) (define GT 6) (define YT 3)

;TASK-1) Write constructors of NTL:

;CONSTRUCTOR

;........................

;TASK-2) Write Selectors for NTL:

;SELECTOR

;.........................

;TASK-3) Write predicate for NTL:

;PREDICATE

;.........................

;TASK-4) Write contract and four more examples: ; Contract: tick-f: ; Purpose: Check the timer of NTL. If it is equal to 0, change the light, otherwise subtract one from counter ; Red --> Green ; Green --> Yellow ; Yellow --> Red

; Example: (check-expect (tick-f (make-NTL "red" 0))(make-NTL "green" GT)) (check-expect (tick-f (make-NTL "red" 4))(make-NTL "red" 3))

;TASK-5) Write template: ;..........................

;TASK-6) Write tick-f function (needs change-light function): ;..........................

;TASK-7) Write contract and four more examples: ; Contract: change-light: ; Purpose: change the light and produce a new traffic light (check-expect (change-light "red")(make-NTL "green" GT))

;TASK-8) Write template: ;..........................

;TASK-9) Write change-light function: ;..........................

;TASK-10) Write contract and more examples:

;Contract: draw-f: ;Purpose: to draw the current traffic light ;(define (draw-f antl) REDL) (check-expect (draw-f (make-NTL "red" 4))REDL)

;TASK-11) Write template: ;..........................

;TASK-12) Write draw-f function: ;..........................

; KeyEvent is one of: ; - "r" ; - "g" ; - "y" ; - all other keyevents

;TASK-13) Write contract and more examples: ; Contract: police-officer: ; Purpose: to change the light according to key event. ; if KeyEvent is r --> "red" ; if KeyEvent is g --> "green" ; if KeyEvent is y --> "yellow" (check-expect (police-officer (make-NTL "red" 4) "r")(make-NTL "red" RT))

;TASK-14) Write template: ;..........................

;TASK-15) Write police-officer function: ;..........................

;NTL --> Images (define (main init) (big-bang init (on-tick tick-f) (on-draw draw-f) (on-key police-officer)))

(main (make-NTL "yellow" 3))