# Can't cull pattern by true/ false

**URL:** <https://discourse.mcneel.com/t/cant-cull-pattern-by-true-false/128487>\
**Category:** Grasshopper\
**Tags:** mac\
**Created:** [August 6, 2021, 9:30pm UTC](https://discourse.mcneel.com/t/cant-cull-pattern-by-true-false/128487 "2021-08-06T21:30:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![omercnaani](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/omercnaani/32/319990_2.png) [@omercnaani](https://discourse.mcneel.com/u/omercnaani)\
**Post date:** [August 6, 2021, 9:30pm UTC](https://discourse.mcneel.com/t/cant-cull-pattern-by-true-false/128487/1 "2021-08-06T21:30:33Z")

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hi, I have multiple curves inside 2 list. I deconstruct the curves point, got the z coordinates and then Im trying to subtract the z coordinates of one list with another. I used “smaller then” and got true/ false list. now when I’m trying to cull pattern by the true/ false list (I want to delete the true item from the list) its doesn’t snt do nothing (as you can see in the param viewer the list branches keep on 142). do someone has any suggestions to solve it?  
attaches script image/.

 ![Screen Shot 2021-08-07 at 0.25.00](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/8/9/4/8942efa26cfbe4e1b3e105aadf1c1e12d7cf8ee4.jpeg)

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**Author:** ![inno](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/inno/32/544036_2.png) [@inno](https://discourse.mcneel.com/u/inno)\
**Post date:** [August 6, 2021, 11:08pm UTC](https://discourse.mcneel.com/t/cant-cull-pattern-by-true-false/128487/2 "2021-08-06T23:08:22Z")

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removing these two flatten might do the trick  
generally speaking, attaching the GH definition with internalized geometries is always the best option, because it allows other to test your file

 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/9/d/2/9d289abf6cadca192c8db53832eb8f5d98b8e746.jpeg)

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**Author:** ![kev.r](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/kev.r/32/766021_2.png) [@kev.r](https://discourse.mcneel.com/u/kev.r)\
**Post date:** [August 7, 2021, 12:47am UTC](https://discourse.mcneel.com/t/cant-cull-pattern-by-true-false/128487/3 "2021-08-07T00:47:09Z")

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Please read this:

> [@Help Us Help You](https://discourse.mcneel.com/t/help-us-help-you/50034):
>
> Asking questions and getting answers is what this forum is all about. Although people are generally very helpful, there are things you can do to improve your chances of getting good and quick answers. Below you will find some suggestions, but don’t think of them as rules and especially don’t think of them as guarantees. 1. Choose a descriptive title for your post Don’t title your question Help! or I have a problem or Deadline tonight!, but actually describe the problem you are having. 2. Be s…

In particular, pay attention to item #3:

**3. Attach minimal versions of all the relevant files**  
If you have a `gh` file you have a question about, attach it to the post. Do not expect that people will recreate a file based on a screen-shot because that’s a lot of pointless work…

-Kevin