Hi, all,

In my model, I have three kinds of decision variables, they are Y_l(n1,n2), X_z(zn), and belta(n1,n2);

When I define these variables as positive continuous variables and fix them as zero (Y_l.fx=0; X_z.fx=0, and belta.fx=0), I got a obvious solution with all variables being zero.

However, when I define these variables as binary variables and also fix them as zero, GAMS return integer infeasibility. This is weird because all variables with zero value must be a feasible solution.

Does anyone know what happened here?

Thank you all in advance.