Modeling a constraint in GMPL

Question

I'm trying to model this constraint in GMPL.

As far as I can understand, j:d_ij < D^k part means " all the 'j's which satisfies the property d_ij < D^k "

I'm pretty new to it so I couldn't manage to model it correctly. Any suggestions?

Answer 1

Ok, did it this way:

s.t. c3{i in N, k in K} : z[k] + sum{j in M : d[i,j] < b[k]} y[j] >= 1;

"b" is used in case of "D".