fig002_insii.pgf

% (c) 2012 Dimitrios Vrettos - d.vrettos@gmail.com
\begin{tikzpicture}[x=2cm,font=\small]
\draw (0,0)circle (1) (0,1) node[ left=1] {$B$};
\begin{scope}[fill=CornflowerBlue, draw=black]
\foreach \x/\xtext in {-.5/t,0/a,.5/r}
\filldraw (\x,.2) circle (2pt) node[above right] {\xtext};
\foreach \y/\ytext in {-.25/u,.25/g}{
\filldraw (\y,-.7) circle (2pt) node[above right] {\ytext};
}
\end{scope}
\end{tikzpicture}