# Error in "Don't unroll the adjoint" paper?

**URL:** <https://discourse.julialang.org/t/error-in-dont-unroll-the-adjoint-paper/47685>\
**Category:** Community\
**Created:** [October 3, 2020, 7:34am UTC](https://discourse.julialang.org/t/error-in-dont-unroll-the-adjoint-paper/47685 "2020-10-03T07:34:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![xiaodai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/xiaodai/32/15937_2.png) [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Post date:** [October 3, 2020, 7:34am UTC](https://discourse.julialang.org/t/error-in-dont-unroll-the-adjoint-paper/47685/1 "2020-10-03T07:34:21Z")

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Referring to the paper [https://arxiv.org/pdf/1810.07951.pdf](https://arxiv.org/pdf/1810.07951.pdf)

I see this passage

![image](https://global.discourse-cdn.com/julialang/original/3X/d/5/d5759ef305cb5752a95ca5697d8556db43b07962.png)

which means it will run into an infinite loop as the end of block#2 goes back to black #2 with no way to exit.

I think it’s meant to say go back to block #1

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<div class="post-metadata">

**Author:** ![xiaodai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/xiaodai/32/15937_2.png) [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Post date:** [October 3, 2020, 8:05am UTC](https://discourse.julialang.org/t/error-in-dont-unroll-the-adjoint-paper/47685/2 "2020-10-03T08:05:31Z")

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Author replied to me in email and that is wrong as pointed out. There is also a new version of the paper which corrected this mistake