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