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