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