%%
%% The LaTeX Companion, 3ed
%%
%% Example 4-2-44 on page I-322 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}


  \addtolength\textwidth{-10pt} % for the line numbers


%StartShownPreambleCommands
\usepackage{algpseudocode}
%StopShownPreambleCommands

\begin{document}
\begin{algorithmic}[1]
\If {$i\leq0$} \State $i\gets1$ \Comment{main case}
\ElsIf {$i>0$} \State $i\gets0$ \EndIf
\end{algorithmic}
\end{document}