− v 2 u 4 + 2 v u 4 + 5 v 2 u 3 − 11 v u 3 + 6 u 3 − 9 v 2 u 2 + 19 v u 2 − 9 u 2 + 6 v 2 u − 11 v u + 5 u + 2 v − 1 {\displaystyle -v^{2}u^{4}+2vu^{4}+5v^{2}u^{3}-11vu^{3}+6u^{3}-9v^{2}u^{2}+19vu^{2}-9u^{2}+6v^{2}u-11vu+5u+2v-1}
