− v 3 u 3 + 2 v 2 u 3 + 2 v 3 u 2 − 4 v 2 u 2 + 3 v u 2 + 3 v 2 u − 4 v u + 2 u + 2 v − 1 {\displaystyle -v^{3}u^{3}+2v^{2}u^{3}+2v^{3}u^{2}-4v^{2}u^{2}+3vu^{2}+3v^{2}u-4vu+2u+2v-1}
