%%
%% The LaTeX Companion, 3ed
%%
%% Example 4-2-46 on page I-325 in "listings --- Pretty-printing program code".
%%
%% 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{159.0pt}

%StartShownPreambleCommands
\usepackage{listings,color}
\lstset{keywordstyle=*\textsf,emph={Sum,N},emph=[2]I,
        emphstyle=\color{blue},emphstyle=[2]\underbar}
%StopShownPreambleCommands

\begin{document}
\begin{lstlisting}[language=Ada]
Sum: Integer;   Sum := 0;
for I in 1..N loop
  Sum := Sum + A(I);
end loop;
\end{lstlisting}
\end{document}