`
F1 = (1 + x*y)^3 * z + y^2 * (1 + x*y) * (4 + 3*x*y)
F2 = y + 3*x * (1 + x*y)^2 * z + 3*x * y^2 * (4 + 3*x*y)
F3 = 2*x - 3*x^2*y - x^3*z
`