K865 :

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