− 2 v 2 u 4 + 3 v u 4 − u 4 + 4 v 2 u 3 − 6 v u 3 + 3 u 3 − 4 v 2 u 2 + 7 v u 2 − 4 u 2 + 3 v 2 u − 6 v u + 4 u − v 2 + 3 v − 2 {\displaystyle -2v^{2}u^{4}+3vu^{4}-u^{4}+4v^{2}u^{3}-6vu^{3}+3u^{3}-4v^{2}u^{2}+7vu^{2}-4u^{2}+3v^{2}u-6vu+4u-v^{2}+3v-2}
