# \[JuMP\] Build an empty constraint with arbitrary size

**URL:** <https://discourse.julialang.org/t/jump-build-an-empty-constraint-with-arbitrary-size/6725>\
**Category:** Optimization (Mathematical)\
**Created:** [October 27, 2017, 5:15pm UTC](https://discourse.julialang.org/t/jump-build-an-empty-constraint-with-arbitrary-size/6725 "2017-10-27T17:15:56Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![brynpickering](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brynpickering/32/2775_2.png) [@brynpickering](https://discourse.julialang.org/u/brynpickering)\
**Post date:** [October 27, 2017, 5:15pm UTC](https://discourse.julialang.org/t/jump-build-an-empty-constraint-with-arbitrary-size/6725/1 "2017-10-27T17:15:56Z")

</div>

I’m trying to build named constraints over arbitrary dimensions using @constraintref e.g.

```julia
function build_empty_constraint(constraint_dimensions)
    # e.g. constraint_dimensions = [1:2, 3:4] 
    @constraintref some_constraint[i for i in constraint_dimensions] 
    return None
end
build_empty_constraint([1:2, 3:4])

```

I assume this would be the same as saying `@constraintref some_constraint[1:2, 3:4] ` But I get the error:

```julia
Syntax error: Expected some_constraint[i for i = constraint_dimensions] to be of form var[...]

```

Is there any way to avoid this?