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