# Why isn't there a \`!in\` or \`!∈\` function/operator?

**URL:** <https://discourse.julialang.org/t/why-isnt-there-a-in-or-function-operator/95654>\
**Category:** General Usage\
**Created:** [March 7, 2023, 9:44am UTC](https://discourse.julialang.org/t/why-isnt-there-a-in-or-function-operator/95654 "2023-03-07T09:44:06Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [March 7, 2023, 10:19am UTC](https://discourse.julialang.org/t/why-isnt-there-a-in-or-function-operator/95654/4 "2023-03-07T10:19:31Z")

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This is an old debate, see e.g.

> [@Non-unicode versions of unicode functions in base/stdlib?](https://discourse.julialang.org/t/non-unicode-versions-of-unicode-functions-in-base-stdlib/13401):
>
> I’m looking at someone else’s code in Julia 1.0 and noticed they use the ∉ (not in) function, which doesn’t seem to have an ascii equivalent (e.g. notin). I realize that it’s possible to get the same functionality by typing ! (el in set), but it reminds me of the deprecation of @test\_approx\_eq in Julia 0.5 in favor of @test a ≈ b atol=ε in Julia 0.6. I have to say that I’m a little alarmed at the existence of unicode-only functions in base. I’ve seen people raise similar concerns in various pla…

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