%%
%% The LaTeX Companion, 3ed
%%
%% Example 4-3-18 on page I-345 in "paracol --- Several text streams aligned".
%%
%% 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{171.0pt}

  \usepackage{microtype} % to improve h&j but it still needs sloppy
  \sloppy

  \setlength\textheight{15.5\baselineskip}

  \DeclareDocumentEnvironment{displayparacol}{mO{}}
          {\begin{paracol}{#1}[\addvspace{\topsep}#2]}
          {\end{paracol}\addvspace{\topsep}}

%StartShownPreambleCommands
\usepackage{paracol}
\definethecounter{footnote}{1}{\alph{footnote}}
% displayparacol as defined in earlier example

%StopShownPreambleCommands

\begin{document}
Text\footnote{A main footnote} with a footnote.
\begin{displayparacol}{2}
  This is text in the English
  language\footnote{We hope!} explaining the
  command \verb=\foo=.
  \switchcolumn
  Dies ist Text\footnote{Ein Satz.} in
  deutscher Sprache\footnote{Schlechter Stil!},
  der das Kommando \verb=\foo= erläutert.
  \switchcolumn  More text.\footnote{C}
  \switchcolumn  Even more text.\footnote{D}
\end{displayparacol}
Further text\footnote{Another main footnote}
with a footnote. More text to fill the page.
\end{document}
