− v 3 u 3 + 2 v 2 u 3 − v u 3 + v 3 u 2 − 5 v 2 u 2 + 4 v u 2 + 4 v 2 u − 5 v u + u − v 2 + 2 v − 1 {\displaystyle -v^{3}u^{3}+2v^{2}u^{3}-vu^{3}+v^{3}u^{2}-5v^{2}u^{2}+4vu^{2}+4v^{2}u-5vu+u-v^{2}+2v-1}
