%%
%% The LaTeX Companion, 3ed
%%
%% Example 8-3-13 on page I-611 in "High-level line commands (originating from epic or eepic)".
%%
%% 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{bxeepic} \setlength{\unitlength}{2mm}
%StopShownPreambleCommands

\begin{document}
\begin{picture}(27,16)(-1,-1)
  \path(-1,-1)(-1,15)(26,15)(26,-1)(-1,-1)
  \linethickness{2pt}
  \drawline[-10](0,0)(10,7)(5,11)
       (0,7)(10,0)(10,7)(0,7)(0,0)(10,0)
  \linethickness{3pt} \roundcap \beveljoin
  \polyline(15.1,0.1)(25,7)(20,11)
       (15,7)(25,0)(25,7)(15,7)(15,0)(25,0)
\end{picture}
\end{document}