# JuMP constraint building with dot call: how to use @dot

**URL:** <https://discourse.julialang.org/t/jump-constraint-building-with-dot-call-how-to-use-dot/90632>\
**Category:** Optimization (Mathematical)\
**Tags:** jump\
**Created:** [November 22, 2022, 9:17am UTC](https://discourse.julialang.org/t/jump-constraint-building-with-dot-call-how-to-use-dot/90632 "2022-11-22T09:17:28Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Shuhua](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/shuhua/32/27618_2.png) [@Shuhua](https://discourse.julialang.org/u/Shuhua)\
**Post date:** [November 22, 2022, 9:17am UTC](https://discourse.julialang.org/t/jump-constraint-building-with-dot-call-how-to-use-dot/90632/1 "2022-11-22T09:17:28Z")

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```julia
julia> using JuMP

julia> model = JuMP.Model()

julia> @variable(model, x[1:3])

julia> @variable(model, y[1:3])

julia> @. @constraint(model, x <= y)

```

gives error: `ERROR: At REPL[19]:1: `@constraint(model, (\<=).(x, y))`: Unsupported constraint expression: we don't know how to parse constraints containing expressions of type :..`

`@constraint(model, @. x <= y)` does not work either, with the following error:

```julia
ERROR: At REPL[20]:1: `@constraint(model, #= REPL[20]:1 =# @ __dot__ x <= y)`: Unsupported constraint expression: we don't know how to parse constraints containing expressions of type :macrocell.

```

I know that we can write `@constraint(model, x .<= y)`, but the constraint can be much more complex in practice with many dots. Does JuMP support the `@.` syntax?

---

<div class="post-metadata">

**Author:** ![odow](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/odow/32/28685_2.png) [@odow](https://discourse.julialang.org/u/odow)\
**Post date:** [November 22, 2022, 4:35pm UTC](https://discourse.julialang.org/t/jump-constraint-building-with-dot-call-how-to-use-dot/90632/2 "2022-11-22T16:35:27Z")

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No. JuMP does not support the `@.` syntax. In general, macros do not compose well.