Hello everyone,

I have some doubts about how to create constraints using a constant value. For example, let’s take the code below.

```
using JuMP, Gurobi
function solve()
#Decision variables
@variable(model, x[m = 1:30, s = 1:5, w = 1:4, d = 1:7], Bin)
for s = 1:5; w = 1:4; d = 1:7
@constraint(model, sum(x[m,s,w,d] for m in 1:9) >= 3)
end
@objective(model, Min, sum(x[m,s,w,d] for m in 1:30, s = 1:5, w = 1:4, d = 1:7))
#-----------------------------------------------------
println("\n\nsolving mathematical model...")
optimize!(model)
status = termination_status(model)
end
```

The solver returned the following error:

ERROR: Operation `sub_mul`

between `Matrix{AffExpr}`

and `Int64`

is not allowed. This most often happens when you write a constraint like `x >= y`

where `x`

is an array and `y`

is a constant. Use the broadcast syntax `x .- y >= 0`

instead.

My doubt is how to use the broadcast syntax, more specifically how to get only a subset of x to build my constraint.

Thank you very much for the support.