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