z 7 a + z 7 a 3 + 4 z 6 a 2 + 2 z 6 a 4 + 2 z 6 + 2 a z 5 + z 5 a + z 5 a 5 + 2 a 2 z 4 − 9 z 4 a 2 − 6 z 4 a 4 − z 4 + a 3 z 3 − 3 z 3 a − 5 z 3 a 3 − 3 z 3 a 5 − 2 a 2 z 2 + 5 z 2 a 2 + 4 z 2 a 4 − z 2 − a 3 z − a z + z a + 3 z a 3 + 2 z a 5 + a 2 − 1 a 2 − 1 a 4 + 2 {\displaystyle {\frac {z^{7}}{a}}+{\frac {z^{7}}{a^{3}}}+{\frac {4z^{6}}{a^{2}}}+{\frac {2z^{6}}{a^{4}}}+2z^{6}+2az^{5}+{\frac {z^{5}}{a}}+{\frac {z^{5}}{a^{5}}}+2a^{2}z^{4}-{\frac {9z^{4}}{a^{2}}}-{\frac {6z^{4}}{a^{4}}}-z^{4}+a^{3}z^{3}-{\frac {3z^{3}}{a}}-{\frac {5z^{3}}{a^{3}}}-{\frac {3z^{3}}{a^{5}}}-2a^{2}z^{2}+{\frac {5z^{2}}{a^{2}}}+{\frac {4z^{2}}{a^{4}}}-z^{2}-a^{3}z-az+{\frac {z}{a}}+{\frac {3z}{a^{3}}}+{\frac {2z}{a^{5}}}+a^{2}-{\frac {1}{a^{2}}}-{\frac {1}{a^{4}}}+2}
