\documentclass[a4paper]{article} \usepackage{oubraces} \begin{document} \title{Braces over and under equations} \author{Donald Arseneau} \vspace{-\fill} \maketitle \thispagestyle{empty} The syntax is: \begin{verbatim} \overunderbraces{upper_braces}{main_formula}{lower_braces} \end{verbatim} Suppose we want the equation: \[ \overunderbraces{&\br{2}{x}& &\br{2}{y}}% {a + b +&c + d +&e + f&+&g + h&+ i + j&+ k + l + m}% {& &\br{3}{z}} = \pi r^2 \] There are seven segments: \begin{verbatim} x y ,-----^-----. ,-----^-----. a + b + c + d + e + f + g + h + i + j + k + l + m = \pi r^2 11111111222222223333344455555666666667777777777... `-----v-----' z \end{verbatim} Insert \texttt{\&} between each segment (where the tips of the braces point) to type the main\_formula: \begin{verbatim} x y ,-----^-----. ,-----^-----. a + b +&c + d +&e + f&+&g + h&+ i + j&+ k + l + m `-----v-----' z \end{verbatim} Each brace should be specified by typing \begin{verbatim} \br{number_of_segments}{label}, \end{verbatim} separated by \texttt{\&} to indicate which segment to start at; use \texttt{\& \&} to skip a segment that has no brace. For our example formula, the upper and lower brace specifiers are: \begin{center} \begin{tabular}{ll} top row: \verb|&\br{2}{x}& &\br{2}{y}| bottom row: \verb|& &\br{3}{z}| \end{tabular} \end{center} Now put them all together: \begin{verbatim} \overunderbraces{&\br{2}{x}& &\br{2}{y}}% {a + b +&c + d +&e + f&+&g + h&+ i + j&+ k + l + m}% {& &\br{3}{z}} = \pi r^2 \end{verbatim} \dots{} and we're done (that code was used to typeset the display at the start of this document). \enlargethispage{2\baselineskip} \vspace*{0.5\baselineskip} \small \noindent This documentation derived from the comments the original package, by Robin Fairbairns (2010-02-22) \end{document}