K754 :

a^2*c^2*x^2*y + 2*b^2*c^2*x^2*y - c^4*x^2*y - 2*a^2*c^2*x*y^2 - 
     b^2*c^2*x*y^2 + c^4*x*y^2 - a^2*b^2*x^2*z + b^4*x^2*z - 2*b^2*c^2*x^2*z - 
     a^4*y^2*z + a^2*b^2*y^2*z + 2*a^2*c^2*y^2*z + 2*a^2*b^2*x*z^2 - b^4*x*z^2 + 
     b^2*c^2*x*z^2 + a^4*y*z^2 - 2*a^2*b^2*y*z^2 - a^2*c^2*y*z^2=0