%%
%% The LaTeX Companion, 3ed
%%
%% Example 8-5-17 on page I-641 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{111.0pt}

%StartShownPreambleCommands
\usepackage{tikz}
\usetikzlibrary{positioning,shapes}
%StopShownPreambleCommands

\begin{document}
\begin{tikzpicture}[line width=1pt]
 \node[draw,circle] (A) {a};   \node[draw] (B) at (2,0.5) {b};
 \node[draw,shape=cloud,below=1cm of A.center] (C) {Hello};
 \node[draw,left=1cm of A.center] (D) {d};
 \draw[<->] (A) -- (B);
 \draw[->,dashed] (C) -| (B);
 \draw[->,blue] (C) sin (D);
\end{tikzpicture}
\end{document}
