− 4 u 2 v 3 − 4 u 2 v 2 + u 2 v + u v 4 − 5 u v 3 + 9 u v 2 − 5 u v + u + v 3 − 4 v 2 + 4 v u v 2 {\displaystyle -{\frac {4u^{2}v^{3}-4u^{2}v^{2}+u^{2}v+uv^{4}-5uv^{3}+9uv^{2}-5uv+u+v^{3}-4v^{2}+4v}{uv^{2}}}}
