− a 10 + 2 z 2 a 8 + 2 a 8 − z 4 a 6 − 2 z 2 a 6 − 2 a 6 + 2 z 2 a 4 + a 4 + z 2 a 2 + a 2 {\displaystyle -a^{10}+2z^{2}a^{8}+2a^{8}-z^{4}a^{6}-2z^{2}a^{6}-2a^{6}+2z^{2}a^{4}+a^{4}+z^{2}a^{2}+a^{2}}
