− z 4 a 12 − 3 z 2 a 12 − 2 a 12 + 3 z 6 a 10 + 11 z 4 a 10 + 11 z 2 a 10 + 3 a 10 − 2 z 8 a 8 − 10 z 6 a 8 − 17 z 4 a 8 − 12 z 2 a 8 − 3 a 8 + 3 z 6 a 6 + 12 z 4 a 6 + 13 z 2 a 6 + 3 a 6 {\displaystyle -z^{4}a^{12}-3z^{2}a^{12}-2a^{12}+3z^{6}a^{10}+11z^{4}a^{10}+11z^{2}a^{10}+3a^{10}-2z^{8}a^{8}-10z^{6}a^{8}-17z^{4}a^{8}-12z^{2}a^{8}-3a^{8}+3z^{6}a^{6}+12z^{4}a^{6}+13z^{2}a^{6}+3a^{6}}