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