u 4 v 3 − u 4 v 2 + u 3 v 4 − 3 u 3 v 3 + 4 u 3 v 2 − 2 u 3 v − u 2 v 4 + 4 u 2 v 3 − 7 u 2 v 2 + 4 u 2 v − u 2 − 2 u v 3 + 4 u v 2 − 3 u v + u − v 2 + v u 2 v 2 {\displaystyle {\frac {u^{4}v^{3}-u^{4}v^{2}+u^{3}v^{4}-3u^{3}v^{3}+4u^{3}v^{2}-2u^{3}v-u^{2}v^{4}+4u^{2}v^{3}-7u^{2}v^{2}+4u^{2}v-u^{2}-2uv^{3}+4uv^{2}-3uv+u-v^{2}+v}{u^{2}v^{2}}}}
