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