− a 4 z 10 + a 6 z 8 − 7 a 4 z 8 + 2 a 2 z 8 + 5 a 6 z 6 − 20 a 4 z 6 + 10 a 2 z 6 − z 6 + 9 a 6 z 4 − 28 a 4 z 4 + 17 a 2 z 4 − 3 z 4 + 7 a 6 z 2 − 17 a 4 z 2 + 12 a 2 z 2 − 2 z 2 + a 6 − 3 a 4 + 3 a 2 {\displaystyle -a^{4}z^{10}+a^{6}z^{8}-7a^{4}z^{8}+2a^{2}z^{8}+5a^{6}z^{6}-20a^{4}z^{6}+10a^{2}z^{6}-z^{6}+9a^{6}z^{4}-28a^{4}z^{4}+17a^{2}z^{4}-3z^{4}+7a^{6}z^{2}-17a^{4}z^{2}+12a^{2}z^{2}-2z^{2}+a^{6}-3a^{4}+3a^{2}}