fig-scaffold-example.tex

\documentclass[tikz,border=7pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage{lmodern,amsmath,amssymb}
\hyphenpenalty=10000
\exhyphenpenalty=10000
\usetikzlibrary{arrows.meta,positioning,calc,fit,backgrounds}
\definecolor{ink}{HTML}{243B4A}
\definecolor{pale}{HTML}{EFF5F7}
\definecolor{warm}{HTML}{FAF5E8}
\tikzset{every node/.style={font=\sffamily\small,text=ink},
 box/.style={draw=ink!65,rounded corners=2pt,fill=pale,align=center,inner sep=7pt},
 warmbox/.style={box,fill=warm},
 arr/.style={-{Latex[length=2mm]},draw=ink!80,line width=.65pt},
 lab/.style={font=\sffamily\footnotesize,fill=white,inner sep=2pt},
 dot/.style={circle,draw=ink!75,fill=white,minimum size=8mm,inner sep=1pt},
 title/.style={font=\sffamily\bfseries\small,align=center}}
\begin{document}\begin{tikzpicture}

\node[title] at (2.6,3.2) {Physical graph};
\node[dot] (n0) at (0,1.6) {$0:\varnothing$};
\node[dot] (n1) at (1.7,1.6) {$1:a$};
\node[dot] (n2) at (3.4,1.6) {$2:b$};
\node[dot] (n3) at (5.1,1.6) {$3:a$};
\draw[arr] (n1)--node[lab,above]{0}(n0);
\draw[arr] (n2)--node[lab,above]{0}(n1);
\draw[arr] (n2) to[bend left=35] node[lab,below]{1}(n0);
\draw[arr] (n3) to[loop above]node[lab]{0}(n3);
\draw[arr] (n3) to[bend left=38]node[lab,below]{1}(n1);
\node[align=center,text width=5.5cm] at (2.6,-.1) {Port 0 of node 3 is a self-loop.\\Port 1 reaches node 1.};
\node[title] at (10.1,3.2) {Labelled unfolding $N_2(3)$};
\node[dot] (a) at (10,2.3) {$a$};
\node[dot] (b) at (8.6,1.1) {$a$};\node[dot] (c) at (11.4,1.1) {$a$};
\node[dot] (d) at (7.9,-.1) {$a$};\node[dot] (e) at (9.3,-.1) {$a$};
\node[dot] (f) at (10.7,-.1) {$\varnothing$};\node (g) at (12.1,-.1) {$\times$};
\draw[arr] (a)--node[lab,left]{0}(b);\draw[arr] (a)--node[lab,right]{1}(c);
\draw[arr] (b)--node[lab,left]{0}(d);\draw[arr] (b)--node[lab,right]{1}(e);
\draw[arr] (c)--node[lab,left]{0}(f);\draw[arr,dashed] (c)--node[lab,right]{1}(g);
\node[font=\sffamily\footnotesize] at (10,-1) {$\varnothing$: unlabelled base \qquad $\times$: missing port};

\end{tikzpicture}\end{document}