K965 :

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