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