%%
%% The LaTeX Companion, 3ed
%%
%% Example 4-2-14 on page I-306 in "Customization keys for typesetting".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{183.0pt}

%StartShownPreambleCommands
\usepackage{relsize,fancyvrb}
%StopShownPreambleCommands

\begin{document}
\begin{Verbatim}[fontsize=\relsize{-2}]
  \sum_{i=1}^n
\end{Verbatim}
A line of text to show the body size.
\begin{Verbatim}[fontshape=sl,fontsize=\Large]
  \sum_{i=1}^n
\end{Verbatim}
\end{document}