a 4 z 6 + a 2 z 6 + a 5 z 5 + 2 a 3 z 5 + a z 5 − 4 a 4 z 4 − 4 a 2 z 4 − 4 a 5 z 3 − 7 a 3 z 3 − 3 a z 3 + 4 a 4 z 2 + 6 a 2 z 2 + 2 z 2 + 3 a 5 z + 5 a 3 z + 3 a z + z a − 2 a 4 − 4 a 2 − 1 {\displaystyle a^{4}z^{6}+a^{2}z^{6}+a^{5}z^{5}+2a^{3}z^{5}+az^{5}-4a^{4}z^{4}-4a^{2}z^{4}-4a^{5}z^{3}-7a^{3}z^{3}-3az^{3}+4a^{4}z^{2}+6a^{2}z^{2}+2z^{2}+3a^{5}z+5a^{3}z+3az+{\frac {z}{a}}-2a^{4}-4a^{2}-1}