Correct way for excluding constraints based on index

Question

Assume the following constraint:

@constraint(model, [i=1:5,j=1:5], a[i] <= b[j])

How do I exclude constraint where i == j from the above? This is simple to do in AMPL but I can't find any similar syntax in JuMP.

Answer 1

@constraint(model, [i=1:5, j=1:5; i != j], a[i] <= b[j])