− 2 v u 4 + 2 u 4 − 2 v 2 u 3 + 8 v u 3 − 4 u 3 + 4 v 2 u 2 − 11 v u 2 + 4 u 2 − 4 v 2 u + 8 v u − 2 u + 2 v 2 − 2 v {\displaystyle -2vu^{4}+2u^{4}-2v^{2}u^{3}+8vu^{3}-4u^{3}+4v^{2}u^{2}-11vu^{2}+4u^{2}-4v^{2}u+8vu-2u+2v^{2}-2v}
