function G=gtest(x)

G =[
[                1+40*(x(1)-x(4)).^3]
[              10+4*(x(2)-2*x(3)).^3]
[ 10*x(3)-10*x(4)-8*(x(2)-2*x(3)).^3]
[ -10*x(3)+10*x(4)-40*(x(1)-x(4)).^3]];