z 5 a 13 − 4 z 3 a 13 + 3 z a 13 + z 6 a 12 − 3 z 4 a 12 + z 2 a 12 + z 7 a 11 − 3 z 5 a 11 + 2 z 3 a 11 − z a 11 + z 8 a 10 − 5 z 6 a 10 + 11 z 4 a 10 − 10 z 2 a 10 + 2 a 10 + 2 z 7 a 9 − 8 z 5 a 9 + 12 z 3 a 9 − 4 z a 9 + z 8 a 8 − 5 z 6 a 8 + 11 z 4 a 8 − 7 z 2 a 8 + 2 a 8 + z 7 a 7 − 3 z 5 a 7 + 4 z 3 a 7 + z 6 a 6 − 2 z 4 a 6 + z 2 a 6 + z 5 a 5 − 2 z 3 a 5 + z 4 a 4 − 3 z 2 a 4 + a 4 {\displaystyle z^{5}a^{13}-4z^{3}a^{13}+3za^{13}+z^{6}a^{12}-3z^{4}a^{12}+z^{2}a^{12}+z^{7}a^{11}-3z^{5}a^{11}+2z^{3}a^{11}-za^{11}+z^{8}a^{10}-5z^{6}a^{10}+11z^{4}a^{10}-10z^{2}a^{10}+2a^{10}+2z^{7}a^{9}-8z^{5}a^{9}+12z^{3}a^{9}-4za^{9}+z^{8}a^{8}-5z^{6}a^{8}+11z^{4}a^{8}-7z^{2}a^{8}+2a^{8}+z^{7}a^{7}-3z^{5}a^{7}+4z^{3}a^{7}+z^{6}a^{6}-2z^{4}a^{6}+z^{2}a^{6}+z^{5}a^{5}-2z^{3}a^{5}+z^{4}a^{4}-3z^{2}a^{4}+a^{4}}
