K1028 :

a^4 b^5 x^2 y+a^6 b c^2 x^2 y-a^5 b^4 x y^2-a b^6 c^2 x y^2-a^6 b^2 c x^2 z-a^4 c^5 x^2 z+a^2 b^6 c y^2 z+b^4 c^5 y^2 z+a^5 c^4 x z^2+a b^2 c^6 x z^2-b^5 c^4 y z^2-a^2 b c^6 y z^2=0