x_1, x_2, x_3, x_4, x_5, x_6, 
x_1^2+2*x_3*x_4+2*x_3*x_5+2*x_3*x_6-x_5
2*x_1*x_2+2*x_1*x_4+2*x_2*x_5+2*x_3*x_6-x_6
2*x_1*x_2+2*x_1*x_6+2*x_2*x_3+x_4*x_5+x_5*x_6-x_2
2*x_1*x_3+2*x_1*x_5+x_2^2+2*x_2*x_6+2*x_4*x_6-x_1
2*x_4+2*x_5+2*x_6+2*x_1+2*x_2+x_3-1
2*x_1^2+2*x_2^2+x_3^2+2*x_4^2+2*x_5^2+2*x_6^2-x_3
