K623 :
a^3*x^2*y - 2*a^2*b*x^2*y + a*b^2*x^2*y - a^2*c*x^2*y + b^2*c*x^2*y + a*c^2*x^2*y - c^3*x^2*y - a^2*b*x*y^2 + 2*a*b^2*x*y^2 - b^3*x*y^2 - a^2*c*x*y^2 + b^2*c*x*y^2 - b*c^2*x*y^2 + c^3*x*y^2 - a^3*x^2*z + a^2*b*x^2*z - a*b^2*x^2*z + b^3*x^2*z + 2*a^2*c*x^2*z - a*c^2*x^2*z - b*c^2*x^2*z - a^3*y^2*z + a^2*b*y^2*z - a*b^2*y^2*z + b^3*y^2*z - 2*b^2*c*y^2*z + a*c^2*y^2*z + b*c^2*y^2*z + a^2*b*x*z^2 - b^3*x*z^2 + a^2*c*x*z^2 + b^2*c*x*z^2 - 2*a*c^2*x*z^2 - b*c^2*x*z^2 + c^3*x*z^2 + a^3*y*z^2 - a*b^2*y*z^2 - a^2*c*y*z^2 - b^2*c*y*z^2 + a*c^2*y*z^2 + 2*b*c^2*y*z^2 - c^3*y*z^2 = 0