− 2 v 2 u 4 + 3 v u 4 − u 4 + 6 v 2 u 3 − 10 v u 3 + 4 u 3 − 7 v 2 u 2 + 15 v u 2 − 7 u 2 + 4 v 2 u − 10 v u + 6 u − v 2 + 3 v − 2 {\displaystyle -2v^{2}u^{4}+3vu^{4}-u^{4}+6v^{2}u^{3}-10vu^{3}+4u^{3}-7v^{2}u^{2}+15vu^{2}-7u^{2}+4v^{2}u-10vu+6u-v^{2}+3v-2}
