− a 4 z 10 + a 6 z 8 − 7 a 4 z 8 + 2 a 2 z 8 + 6 a 6 z 6 − 18 a 4 z 6 + 11 a 2 z 6 − z 6 − a 8 z 4 + 11 a 6 z 4 − 23 a 4 z 4 + 19 a 2 z 4 − 4 z 4 − 2 a 8 z 2 + 9 a 6 z 2 − 15 a 4 z 2 + 14 a 2 z 2 − 4 z 2 − a 8 + 3 a 6 − 5 a 4 + 5 a 2 − 1 {\displaystyle -a^{4}z^{10}+a^{6}z^{8}-7a^{4}z^{8}+2a^{2}z^{8}+6a^{6}z^{6}-18a^{4}z^{6}+11a^{2}z^{6}-z^{6}-a^{8}z^{4}+11a^{6}z^{4}-23a^{4}z^{4}+19a^{2}z^{4}-4z^{4}-2a^{8}z^{2}+9a^{6}z^{2}-15a^{4}z^{2}+14a^{2}z^{2}-4z^{2}-a^{8}+3a^{6}-5a^{4}+5a^{2}-1}