# Problem swap: the point s is on an edge

**URL:** <https://community.freefem.org/t/problem-swap-the-point-s-is-on-an-edge/2772>\
**Category:** General Discussion\
**Created:** [November 2, 2023, 11:49am UTC](https://community.freefem.org/t/problem-swap-the-point-s-is-on-an-edge/2772 "2023-11-02T11:49:46Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jna1g18](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jna1g18](https://community.freefem.org/u/jna1g18)\
**Post date:** [November 2, 2023, 11:49am UTC](https://community.freefem.org/t/problem-swap-the-point-s-is-on-an-edge/2772/1 "2023-11-02T11:49:46Z")

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Hi all, I received the following message while running my code:

“_Problem swap: the point s is on an edge =\> swap 0 [480689017::1911157094,1911153325,1911153324,{480688784 4} {480696710 0} {480696711 0}]_”

Can anyone tell me what this means? Many thanks!

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**Author:** ![marchywka](https://avatars.discourse-cdn.com/v4/letter/m/ee59a6/32.png) [@marchywka](https://community.freefem.org/u/marchywka)\
**Post date:** [November 3, 2023, 8:09am UTC](https://community.freefem.org/t/problem-swap-the-point-s-is-on-an-edge/2772/2 "2023-11-03T08:09:43Z")

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Someone may know off hand but if it is obscure it may help to post the code generating that output. If it is from FreeFem, you could grep the source code for parts of the phrase  
likely to be present as a literal.