z 3 a 11 − z a 11 + 2 z 4 a 10 − 2 z 2 a 10 + 2 z 5 a 9 − 2 z 3 a 9 + z a 9 + z 6 a 8 + z 2 a 8 − a 8 + 3 z 5 a 7 − 4 z 3 a 7 + z a 7 + z 6 a 6 − z 4 a 6 + z 5 a 5 − z 3 a 5 − z a 5 + z 4 a 4 − 3 z 2 a 4 + 2 a 4 {\displaystyle z^{3}a^{11}-za^{11}+2z^{4}a^{10}-2z^{2}a^{10}+2z^{5}a^{9}-2z^{3}a^{9}+za^{9}+z^{6}a^{8}+z^{2}a^{8}-a^{8}+3z^{5}a^{7}-4z^{3}a^{7}+za^{7}+z^{6}a^{6}-z^{4}a^{6}+z^{5}a^{5}-z^{3}a^{5}-za^{5}+z^{4}a^{4}-3z^{2}a^{4}+2a^{4}}
