# Why are ↗, ↖ not useable as Binary infix operators?

**URL:** <https://discourse.julialang.org/t/why-are-not-useable-as-binary-infix-operators/6777>\
**Category:** General Usage\
**Tags:** question, infix\
**Created:** [October 30, 2017, 3:19pm UTC](https://discourse.julialang.org/t/why-are-not-useable-as-binary-infix-operators/6777 "2017-10-30T15:19:48Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![chakravala](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chakravala/32/6832_2.png) [@chakravala](https://discourse.julialang.org/u/chakravala)\
**Post date:** [October 30, 2017, 3:19pm UTC](https://discourse.julialang.org/t/why-are-not-useable-as-binary-infix-operators/6777/1 "2017-10-30T15:19:48Z")

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It seems to be possible to define all sorts of binary infix operators, like `∨, ⋖, ⋗, ⊴` work fine.

But why can’t I assign `↗, ↖` as binary infix operators? they are `\nearrow` and `\nwarrow`.

For example, in my Dendriform.jl package:

```Julia
julia> [1,2,3] ⋖ [1,3,1]
true

julia> [1,2,3] ↗ [3,2,1]
ERROR: syntax: extra token "↗" after end of expression
Stacktrace:
 [1] macro expansion at ./REPL.jl:97 [inlined]
 [2] (::Base.REPL.##1#2{Base.REPL.REPLBackend})() at ./event.jl:73

```

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**Author:** ![mauro3](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mauro3/32/292_2.png) [@mauro3](https://discourse.julialang.org/u/mauro3)\
**Post date:** [October 30, 2017, 3:38pm UTC](https://discourse.julialang.org/t/why-are-not-useable-as-binary-infix-operators/6777/2 "2017-10-30T15:38:00Z")

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Allowed infix operators are pre-defined, I think it is this: [https://github.com/JuliaLang/julia/blob/4aa4652974646bad0d9f4a3e18b4f0ea3aa1443f/src/julia-parser.scm](https://github.com/JuliaLang/julia/blob/4aa4652974646bad0d9f4a3e18b4f0ea3aa1443f/src/julia-parser.scm)

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**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [October 30, 2017, 3:50pm UTC](https://discourse.julialang.org/t/why-are-not-useable-as-binary-infix-operators/6777/3 "2017-10-30T15:50:06Z")

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See:  
[https://github.com/JuliaLang/julia/issues/23224](https://github.com/JuliaLang/julia/issues/23224)  
We’d eventually like to allow this, but the basic problem is that we haven’t decided what precedence to use for things like `↗`. (The precedence of an operator is set in the parser and needs to be decided more or less permanently. It is difficult to decide what to do with Unicode symbols that don’t have a standard mathematical meaning.)