$ \begin{tikzpicture}[baseline] \node (S) [circle,draw] {$S$}; \filldraw (S.157) circle (.5mm); \draw (S.135) .. controls +(135:3mm) and +(90:3mm) .. (S.90); \draw (S.45) -- +(45:3mm); \draw (S.0) -- +(0:3mm); \draw (S.-45) node [below] {$\cdot$}; \draw (S.-90) node [below] {$\cdot$}; \draw (S.-135) node [below] {$\cdot$}; \draw (S.180) -- +(180:3mm); \end{tikzpicture} %= %\begin{tikzpicture}[baseline] % \node[xshift=2cm] (S') [circle,draw] {$^\bullet S$}; % \draw (S'.135) node[left] {$\bullet$} -- +(135:3mm); % \draw (S'.90) .. controls +(90:3mm) and + (45:3mm) .. (S'.45); % \draw (S'.0) -- +(0:3mm); % \draw (S'.-45) node [below] {$\cdot$}; % \draw (S'.-90) node [below] {$\cdot$}; % \draw (S'.-135) node [below] {$\cdot$}; % \draw (S'.180) -- +(180:3mm); %\end{tikzpicture} = 0 $