x^4*y^3 - x^4*y^2 + 1/3*x^4*y + 2*x^3*y^3 - 3*x^3*y^2 + 5/3*x^3*y - 1/3*x^3 + 
    x^2*y^4 - x^2*y^3 - 2/3*x^2*y^2 + x^2*y - 1/3*x^2 + 4/3*x*y^4 - 3*x*y^3 + 
    7/3*x*y^2 - 2/3*x*y + 1/3*y^5 - y^4 + y^3 - 1/3*y^2