− u 4 v 4 − u 4 v 3 − 2 u 3 v 4 + 6 u 3 v 3 − 5 u 3 v 2 + u 3 v + u 2 v 4 − 6 u 2 v 3 + 11 u 2 v 2 − 6 u 2 v + u 2 + u v 3 − 5 u v 2 + 6 u v − 2 u − v + 1 u 2 v 2 {\displaystyle -{\frac {u^{4}v^{4}-u^{4}v^{3}-2u^{3}v^{4}+6u^{3}v^{3}-5u^{3}v^{2}+u^{3}v+u^{2}v^{4}-6u^{2}v^{3}+11u^{2}v^{2}-6u^{2}v+u^{2}+uv^{3}-5uv^{2}+6uv-2u-v+1}{u^{2}v^{2}}}}
