− 2 v 2 u 4 + 2 v u 4 + 6 v 2 u 3 − 8 v u 3 + 2 u 3 − 6 v 2 u 2 + 13 v u 2 − 6 u 2 + 2 v 2 u − 8 v u + 6 u + 2 v − 2 {\displaystyle -2v^{2}u^{4}+2vu^{4}+6v^{2}u^{3}-8vu^{3}+2u^{3}-6v^{2}u^{2}+13vu^{2}-6u^{2}+2v^{2}u-8vu+6u+2v-2}
