Hi Everyone,

I need help in implementing an optimization problem concerning the Vehicle Routing in AIMMS.

I am currently indiciating the constraints for the mathematical problem. The index i and j is for the customers or nodes and k is for the vehicles.

I now want to implement the constraint, that each vehicle can only leave the material-depot once. The material-depot i indicated by the value “0” for i or j.

The mathematical formulation is now: **sum x(0,j,k) <= 1**

**In AIMMS it is indicated as follows: sum(j, x((0,j,k) <= 1)**

In this case, the index i is directly indicated with the value 0 for the depot but wenn I integrate this formulation in AIMMS, I receive a warning: “The symbol 0 is not expected”.

How can I indicate this formulation in AIMMS in the correct way so that the system understands that “0” is the value for i?

Maybe someone can help me.. Thank you in advance!! :)

**Best answer by gdiepen**