$\sum{□}$ $\sum\limits_{□}{□}$ $\sum\limits_{□}^{□}{□}$ $\sum\limits_{i=0}^{n}{i}$
$\prod{□}$ $\prod\limits_{□}{□}$ $\prod\limits_{□}^{□}{□}$ $\prod\limits_{i=0}^{n}{i}$
$\coprod{□}$ $\coprod_{□}{□}$ $\coprod\limits_{□}^{□}{□}$ $\coprod\limits_{i=0}^{n}{i}$
$\sum_{\substack{0 \le i \le m \\ 0 \lt j \lt n}} P(i, j)$ $\sideset{_{*}^{*}}{_{*}^{*}}{\prod}$