\chapter{Glossary of Terms}
\markright{Glossary of Terms} % new right header
\label{chap.glossary}
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\begin{description}
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\item[left-to-right (LR) mode] Like paragraph mode, but no line breaks are inserted. The \cmmd{mbox} command is processed in LR mode.
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\item[math mode] The mode for typesetting mathematics. 
Math mode is indicated in in-line text between \cmmd{(}  \cmmd{)} commands or pairs of \$ symbols.
The \enviro{equation} and similar environments also work in math mode.
(Note that matched \$ s within these environments toggles back to paragraph mode.)
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\item[mode] One of three typesetting modes of \LaTeX : paragraph mode, math mode, left-to-right (LR) mode.
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\item[paragraph mode] The mode for processing ordinary text.
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\item[preamble] The material in a \LaTeX\ source file before the 
\verb=\begin{document}= command. 
Used to set the \cmmd{documentclass}, packages (\enviro{usepackage}), and other formatting commands.
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\end{description}
