証明\cdots>\mu_l} q^{\mu_1+\cdots+\mu_l}\,x^l \\ =\sum_{\lambda}q^{|\lambda |}\,q^{l(\lambda)(l(\lambda)-1)/2}\,x^{l(\lambda)} \\ =\sum_{\lambda}q^{|\lambda |}\,q^{\lambda_1(\lambda_1-1)/2}\,x^{\lambda_1}\\ = \sum_{l\geq 0} \left( \prod_{j…

2次形式の符号数． Morse 理論．