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