# Big-bang returns zero

**URL:** <https://racket.discourse.group/t/big-bang-returns-zero/862>\
**Category:** Questions & Answers\
**Tags:** question, drracket\
**Created:** [April 8, 2022, 2:16pm UTC](https://racket.discourse.group/t/big-bang-returns-zero/862 "2022-04-08T14:16:20Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![osman44](https://avatars.discourse-cdn.com/v4/letter/o/85f322/32.png) [@osman44](https://racket.discourse.group/u/osman44)\
**Post date:** [April 8, 2022, 2:16pm UTC](https://racket.discourse.group/t/big-bang-returns-zero/862/1 "2022-04-08T14:16:20Z")

</div>

I am following through the book of "Realm Of Racket" and typed in exactly as it is on the book a landing a UFO animation everything seemed to work until i put in the code for stopping the programming.Specially this part "state-is-600"

(define (state-is-600 current-state)  
(\<= current-state 600))

(big-bang 0  
(on-tick add-3-to-state)  
(to-draw draw-a-ufo-onto-an-empty-scene)  
(stop-when state-is-600))

i did make the sure the codes were written correctly and formatted appropriately,and all it does is return zero each time i run the program any suggestions please.Here is the full code

#lang racket

(require 2htdp/universe 2htdp/image)

(define WIDTH 600)  
(define HEIGHT 600)

(define (add-3-to-state current-state)  
( + current-state 3))  
(define (draw-a-ufo-onto-an-empty-scene current-state)  
(place-image IMAGE-of-UFO (/ WIDTH 2) current-state  
(empty-scene WIDTH HEIGHT)))

```
  (define IMAGE-of-UFO .)

```

(define (state-is-600 current-state)  
(\<= current-state 600))

(big-bang 0  
(on-tick add-3-to-state)  
(to-draw draw-a-ufo-onto-an-empty-scene)  
(stop-when state-is-600))

disclaimer: MAGE-of-UFO does have an image it wont let me copy the image

---

<div class="post-metadata">

**Author:** ![EmEf](https://avatars.discourse-cdn.com/v4/letter/e/53a042/32.png) [@EmEf](https://racket.discourse.group/u/EmEf)\
**Post date:** [April 8, 2022, 4:24pm UTC](https://racket.discourse.group/t/big-bang-returns-zero/862/2 "2022-04-08T16:24:15Z")

</div>

Do you want \>= instead of \<= in `state-is-600`?

The code in the book is available in the installed Racket download: File -\> Open Require Path -\> enter: realm -\> collects/realm. Now choose a chapter.