The objective function is the following:
(x(1)+x(2)) * (x(1)/(x(1)+x(2)))^2+(x(3)+x(4)) * (x(3)/(x(3)+x(4)))^2 + (x(5)+x(6)) * (x(5)/(x(5)+x(6)))^2 + (x(7)+x(8)) * (x(7)/(x(7)+x(8)))^2

subject to some constrains.

I know there is a {real affine}.\ {real affine} in this objective function. I don’t know how to avoid this problem.