\input{figures/exterior_paths} \begin{figure}[htbp] \centering \begin{tikzpicture}[line width=.75pt,line cap=round,line join=round] \begin{scope}[xshift=-5.15cm,scale=.62] \drawDodecahedralExterior \draw (portNW)--(v0)--(portNE); \draw (portSW)--(v1)--(portSE); \draw[line width=1.45pt] (v0)--(v1); \fill (v0) circle[radius=1.8pt]; \fill (v1) circle[radius=1.8pt]; \node[font=\small,inner sep=1pt,anchor=east] at (1.05,.68) {$0$}; \node[font=\small,inner sep=1pt,anchor=east] at (1.05,-.68) {$1$}; \node[font=\normalsize] at (.35,-4.40) {$D=L_0$}; \end{scope} \begin{scope}[scale=.62] \drawDodecahedralExterior \node[font=\small,inner sep=1pt,anchor=south west] at (-.39,1.54) {$9$}; \node[font=\small,inner sep=1pt,anchor=south west] at (2.29,1.70) {$10$}; \node[font=\small,inner sep=1pt,anchor=north west] at (2.29,-1.70) {$2$}; \node[font=\small,inner sep=1pt,anchor=north west] at (-.39,-1.54) {$11$}; \node[font=\normalsize] at (.35,-4.40) {$E$}; \end{scope} \begin{scope}[xshift=5.15cm,scale=.62] \drawDodecahedralExterior \draw (portNW)--(1.00277702,0.18193783); \draw (1.16889297,-0.18193783)--(portSE); \draw (portNE)--(portSW); \node[font=\normalsize] at (.35,-4.40) {$K_2$}; \end{scope} \end{tikzpicture} \caption{The dodecahedron $D$, the common exterior $E$, and $K_2$, shown with the same planar exterior. Delete the portion inside the dashed circle, including the bold edge $01$, to obtain $E$. Its four ends lead to the labelled vertices $9,10,2,11$, in northwest, northeast, southeast and southwest order. Reinsert two crossing arcs to obtain $K_2$; the northwest--southeast arc passes underneath. The same four ends are used in Figure~\ref{fig:octahedron}.} \label{fig:exterior-webs} \label{fig:dodecahedron-exterior} \end{figure}