# Formula will not allow a line to the left of an existing line

**URL:** <https://discourse.shapr3d.com/t/formula-will-not-allow-a-line-to-the-left-of-an-existing-line/37166>\
**Category:** Modeling Questions\
**Created:** [March 22, 2025, 9:57pm UTC](https://discourse.shapr3d.com/t/formula-will-not-allow-a-line-to-the-left-of-an-existing-line/37166 "2025-03-22T21:57:49Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![mruseless](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@mruseless](https://discourse.shapr3d.com/u/mruseless)\
**Post date:** [March 22, 2025, 9:57pm UTC](https://discourse.shapr3d.com/t/formula-will-not-allow-a-line-to-the-left-of-an-existing-line/37166/1 "2025-03-22T21:57:49Z")

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I’m sketching a wall for layout of some wainscoting. I drew a vertical line pattern to establish spacing, now I’m adding more vertical lines to represent the width of the stiles (3.5"). However, if I change the measurement between the two lines to a variable (StileWidth), the app puts the line to the right of my existing line. I deleted the new line and drew it the left, but as soon as I assign the variable, it moves to the right side again. I tried making the distance negative -(StileWidth), but the app said this is an invalid expression.

Any help is appreciated.  
Thanks!  
Eric

 ![Wainscot issue](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/0/6/06cba62ef374aab458daccbf8597a45c62d44bdc.jpeg)

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**Author:** ![mruseless](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@mruseless](https://discourse.shapr3d.com/u/mruseless)\
**Post date:** [March 22, 2025, 10:09pm UTC](https://discourse.shapr3d.com/t/formula-will-not-allow-a-line-to-the-left-of-an-existing-line/37166/2 "2025-03-22T22:09:15Z")

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It must have something to do with the pattern constraint. I deleted this constraint and now it will allow a line to the left. However, I didn’t have this issue at the other end of the pattern so still not sure why the problem is happening.

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**Author:** ![Bob3DPO](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@Bob3DPO](https://discourse.shapr3d.com/u/Bob3DPO)\
**Post date:** [March 23, 2025, 1:09am UTC](https://discourse.shapr3d.com/t/formula-will-not-allow-a-line-to-the-left-of-an-existing-line/37166/3 "2025-03-23T01:09:45Z")

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> [@mruseless](#):
>
> I tried making the distance negative -(StileWidth), but the app said this is an invalid expression.

Hi Eric,

Try (-1) \* StileWidth

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<div class="post-metadata">

**Author:** ![mruseless](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@mruseless](https://discourse.shapr3d.com/u/mruseless)\
**Post date:** [March 23, 2025, 2:01pm UTC](https://discourse.shapr3d.com/t/formula-will-not-allow-a-line-to-the-left-of-an-existing-line/37166/4 "2025-03-23T14:01:15Z")

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Hi Bob3DPO, love the moniker by the way.  
Thanks for the suggestion but it didn’t work.

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**Author:** ![Bob3DPO](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@Bob3DPO](https://discourse.shapr3d.com/u/Bob3DPO)\
**Post date:** [March 23, 2025, 3:42pm UTC](https://discourse.shapr3d.com/t/formula-will-not-allow-a-line-to-the-left-of-an-existing-line/37166/5 "2025-03-23T15:42:56Z")

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Curious. I use this type of expression often to change sign of value.

 ![IMG_0411](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/4/f/4f8f6b6199d8baaf17a505eabd5ceb7cda7f03f9.jpeg)

Then hit enter:

 ![IMG_0412](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/9/2/9264fc628022454df742ba0d468ebc7aff00053b.jpeg)

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<div class="post-metadata">

**Author:** ![mruseless](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@mruseless](https://discourse.shapr3d.com/u/mruseless)\
**Post date:** [March 23, 2025, 4:54pm UTC](https://discourse.shapr3d.com/t/formula-will-not-allow-a-line-to-the-left-of-an-existing-line/37166/6 "2025-03-23T16:54:19Z")

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It works in other contexts, but wouldn’t work in this particular situation. I must not be understanding all the constraints in place, or perhaps this is a bug.