Hi! I’m doing a supply chain optimization using AIMMS for my master project and I have a problem with my binary determinant variable as well as the result error computed. Since this is my first time using AIMMS, I am not sure on how to debug it.

The constraint of my binary is X(i,l,g,g2) + X(i,l,g2,g) ; where g≠g2.

After I run the program, it says

Warning: The rows "TransportationBinary(liquid hydrogen,truck,g1,g3)" and "TransportationBinary(liquid hydrogen,truck,g3,g1)" are equal in the generated mathematical program "MinimizeDailyCost". This may lead to non-unique shadow prices. For more information regarding potential causes and consequences, see the help associated with the option "Warning_duplicate_row".

Can anyone help me explain what is the problem? I am also confuse on which section to declare the g≠g2 in the transportation constraint (g represents the grid squares/ supply demand location).

Appreciate your help!

**Best answer by deannezhang**