bending-edges-with-tikz.tex

% Answer for http://tex.stackexchange.com/a/121348/828, which I was also answered (more thorougly, but with equal endresult) by "Torbjørn T." some minutes before me: http://tex.stackexchange.com/a/121346/828

\documentclass{article}
\usepackage{tikz}
	\usetikzlibrary{arrows}
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}

\begin{document}
\begin{tikzpicture}[->,node distance=2.5cm,auto,main node/.style={rectangle,rounded corners,draw,align=center}]

\node [main node] (A) {$A$};
\node [main node] (D) [below left of=A] {$D$};
\node [main node] (B) [below of=D] {$B$};
\node [main node] (E) [below right of=A] {$E$};
\node [main node] (C) [below of=E] {$C$};

\path (A) edge node [left] {$d$} (D);
\path (A) edge node [right] {$e$} (E);
\path (D) edge node [right] {$b$} (B);
\path (E) edge node [left] {$c$} (C);
\path (B) edge [out=135,in=180] node [left] {$a$} (A);
\path (C) edge [out=45,in=0] node [right] {$a$} (A);

\end{tikzpicture}
\end{document}