a 12 − 4 z 2 a 10 − 3 a 10 + 3 z 4 a 8 + 3 z 2 a 8 + 4 z 4 a 6 + 7 z 2 a 6 + 3 a 6 + z 4 a 4 {\displaystyle a^{12}-4z^{2}a^{10}-3a^{10}+3z^{4}a^{8}+3z^{2}a^{8}+4z^{4}a^{6}+7z^{2}a^{6}+3a^{6}+z^{4}a^{4}}
