− 2 v 2 u 4 + 2 v u 4 + 4 v 2 u 3 − 4 v u 3 + 2 u 3 − 4 v 2 u 2 + 5 v u 2 − 4 u 2 + 2 v 2 u − 4 v u + 4 u + 2 v − 2 {\displaystyle -2v^{2}u^{4}+2vu^{4}+4v^{2}u^{3}-4vu^{3}+2u^{3}-4v^{2}u^{2}+5vu^{2}-4u^{2}+2v^{2}u-4vu+4u+2v-2}
