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