%%
%% The LaTeX Companion, 3ed
%%
%% Example 8-5-7 on page I-637 in "Basic objects".
%%
%% 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{99.0pt}

%StartShownPreambleCommands
\usepackage{tikz}
%StopShownPreambleCommands

\begin{document}
\tikz\path[draw=blue,line width=1pt,scale=4]
  (-1/4,0) -- (-1/8, 0)
  .. controls ++(135:1/8) and ++(250:1/8) .. (0,1/4)
  .. controls ++(290:1/8) and ++(45:1/8)  .. (1/8,0) -- (1/4,0) ;
\end{document}