− a 4 z 10 + 2 a 6 z 8 − 6 a 4 z 8 + 2 a 2 z 8 − a 8 z 6 + 10 a 6 z 6 − 15 a 4 z 6 + 10 a 2 z 6 − z 6 − 4 a 8 z 4 + 18 a 6 z 4 − 21 a 4 z 4 + 17 a 2 z 4 − 4 z 4 − 5 a 8 z 2 + 15 a 6 z 2 − 16 a 4 z 2 + 12 a 2 z 2 − 4 z 2 − 2 a 8 + 5 a 6 − 5 a 4 + 3 a 2 {\displaystyle -a^{4}z^{10}+2a^{6}z^{8}-6a^{4}z^{8}+2a^{2}z^{8}-a^{8}z^{6}+10a^{6}z^{6}-15a^{4}z^{6}+10a^{2}z^{6}-z^{6}-4a^{8}z^{4}+18a^{6}z^{4}-21a^{4}z^{4}+17a^{2}z^{4}-4z^{4}-5a^{8}z^{2}+15a^{6}z^{2}-16a^{4}z^{2}+12a^{2}z^{2}-4z^{2}-2a^{8}+5a^{6}-5a^{4}+3a^{2}}