x, y, z, a, b, c, d, 
d*x+c*y*z-x*(a*y^2+b*z^2+x^2)
d*y+c*z*x-x*(a*z^2+b*x^2+y^2)
d*z+c*x*y-x*(a*x^2+b*y^2+z^2)
