GAMS World Forum

Hello, I have a question regarding sum limits. I can find how to sum over an entire set, which is not that difficult. When trying to find how to sum up to some limit, i cannot find anything on how to do this in GAMS. This is (one of the) function(s) i'd like to model: ∑_(t=1)^(f_j-g_j+e_j) X_ajt ≥1,...