− v u 7 + u 7 + 2 v u 6 − 2 u 6 − 2 v u 5 + 2 u 5 + 2 v u 4 − 2 u 4 − 2 v u 3 + 2 u 3 + 2 v u 2 − 2 u 2 − 2 v u + 2 u + v − 1 {\displaystyle -vu^{7}+u^{7}+2vu^{6}-2u^{6}-2vu^{5}+2u^{5}+2vu^{4}-2u^{4}-2vu^{3}+2u^{3}+2vu^{2}-2u^{2}-2vu+2u+v-1}
