Type BC residue expansion identity
Fix k≥1k\geq 1k≥1 and c∈(0,∞)c\in(0,\infty)c∈(0,∞). Let α1,…,αk\alpha_1,\ldots,\alpha_kα1,…,αk be real numbers and let F(z1,…,zk)F(z_1,\ldots,z_k)F(z1,…,zk) satisfy αk=0\alpha_k=0αk=0, αj>αj+1+c\alpha_j>\alpha_{j+1}+cαj>αj+1+c for 1≤j≤k−11\leq j\leq k-11≤j≤k−1…