\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \)
\( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \)
\(
\def\ccSum #1#2#3{
\sum_{#1}^{#2}{#3}
}
\def\ccProd #1#2#3{
\sum_{#1}^{#2}{#3}
}\)