In AMPL, I can use something like:
set Time ordered;
s.t. Inv{t in Time: ord(t) >=2}: Inv[t]= Inv[prev(t)] + ordered[prev(t)] - shipped[t];
I know I can use numbered index and use t-1 in this case. But if the elements of the set are defined using strings or expressions, then what should I do?
I am not sure if there is similar syntax in JuMP to do similar things for the ord() and prev() functions in ampl.