K518 :
-a^6*x^2*y + 3*a^4*b^2*x^2*y - 3*a^2*b^4*x^2*y + b^6*x^2*y -   4*b^4*c^2*x^2*y + a^2*c^4*x^2*y + 3*b^2*c^4*x^2*y - a^6*x*y^2 +   3*a^4*b^2*x*y^2 - 3*a^2*b^4*x*y^2 + b^6*x*y^2 + 4*a^4*c^2*x*y^2 -   3*a^2*c^4*x*y^2 - b^2*c^4*x*y^2 + a^6*x^2*z - a^2*b^4*x^2*z -   3*a^4*c^2*x^2*z - 3*b^4*c^2*x^2*z + 3*a^2*c^4*x^2*z + 4*b^2*c^4*x^2*z -   c^6*x^2*z + a^4*b^2*y^2*z - b^6*y^2*z +   3*a^4*c^2*y^2*z + 3*b^4*c^2*y^2*z - 4*a^2*c^4*y^2*z - 3*b^2*c^4*y^2*z +   c^6*y^2*z + a^6*x*z^2 - 4*a^4*b^2*x*z^2 + 3*a^2*b^4*x*z^2 -   3*a^4*c^2*x*z^2 + b^4*c^2*x*z^2 + 3*a^2*c^4*x*z^2 -   c^6*x*z^2 - 3*a^4*b^2*y*z^2 + 4*a^2*b^4*y*z^2 - b^6*y*z^2 -   a^4*c^2*y*z^2 + 3*b^4*c^2*y*z^2 - 3*b^2*c^4*y*z^2 + c^6*y*z^2 = 0