y1, y2, y3, y4, x1, x2, x3, x4, a, b, g, 
-x1^3+9*g*x1-3*g*x2-3*g*x3-3*g*x4+3*x1-3*y1
-b*y1+a+x1
-x2^3-3*g*x1+9*g*x2-3*g*x3-3*g*x4+3*x2-3*y2
-b*y2+a+x2
-x3^3-3*g*x1-3*g*x2+9*g*x3-3*g*x4+3*x3-3*y3
-b*y3+a+x3
-x4^3-3*g*x1-3*g*x2-3*g*x3+9*g*x4+3*x4-3*y4
-b*y4+a+x4
