u 4 ( − v 2 ) − u 3 v 3 + u 3 v 2 − u 3 − u 2 v 2 − u v 4 + u v 2 − u v − v 2 u 2 v 2 {\displaystyle {\frac {u^{4}\left(-v^{2}\right)-u^{3}v^{3}+u^{3}v^{2}-u^{3}-u^{2}v^{2}-uv^{4}+uv^{2}-uv-v^{2}}{u^{2}v^{2}}}}
