```
using JuMP
# Block1
M = Model()
@variable(M, x[1:3] >= 1)
# Block2
M = Model()
@variable(M, x[1:3] .>= 1)
# Block3
M = Model()
@variable(M, x[1:3])
@constraint(M, x[1:3] >= 1)
# Block4
M = Model()
@variable(M, x[1:3])
@constraint(M, x[1:3] .>= 1)
```

Block1: OK.

Block2: OK.

Block3: Not OK.

Block4: OK.

Why? And what is the most correct way to define vectorized variables and constraints with `JuMP`

?

Many thanks!