I am trying to code in the following line which I want to minimize as the objective of the model
A:=sum(i in points,j in placement) (MAX((xij(i,j)*x(i)-xij(i,j+1)*x(i)),(xij(i,j)*y(i)-xij(i,j+1)*y(i))+MAX(abs(xij(i,1)*x(i)-Fx),abs(xij(i,1)*y(i)-Fy)))+MAX(abs(xij(i,16)*x(i)-Fx),abs(xij(i,16)*y(i)-Fy)))
However I am running into some problems with MAX and abs. These functions do not appear to allow me to have decision variables as part of the elements they are evaluating.
If anyone can confirm this that would be helpful. Any help in implementign the desired code as well would be great.