− a 4 z 10 + 2 a 6 z 8 − 7 a 4 z 8 + a 2 z 8 − a 8 z 6 + 11 a 6 z 6 − 20 a 4 z 6 + 5 a 2 z 6 − 4 a 8 z 4 + 22 a 6 z 4 − 29 a 4 z 4 + 9 a 2 z 4 − 5 a 8 z 2 + 20 a 6 z 2 − 20 a 4 z 2 + 8 a 2 z 2 − 3 a 8 + 7 a 6 − 6 a 4 + 3 a 2 {\displaystyle -a^{4}z^{10}+2a^{6}z^{8}-7a^{4}z^{8}+a^{2}z^{8}-a^{8}z^{6}+11a^{6}z^{6}-20a^{4}z^{6}+5a^{2}z^{6}-4a^{8}z^{4}+22a^{6}z^{4}-29a^{4}z^{4}+9a^{2}z^{4}-5a^{8}z^{2}+20a^{6}z^{2}-20a^{4}z^{2}+8a^{2}z^{2}-3a^{8}+7a^{6}-6a^{4}+3a^{2}}