&= \frac{1}{\qi{2n-1}}
\begin{tikzpicture}[baseline]
    \clip (-1,-1.3) rectangle (1,1.3);

    \node at (0,.6) (top) [ellipse,draw] {$ \hspace{.15 cm} S \hspace{.15cm} $};
    \node at (0,-.6) (bottom) [ellipse,draw]{$ \hspace{.15 cm} S \hspace{.15cm} $};
    \filldraw (top.180) circle (.5mm);
    \filldraw (bottom.180) circle (.5mm);    

    \node at (top.0) (invisible) [right] {};
    \draw (invisible.90)--++(90:2cm);
    \draw (invisible.90) -- ++ (-90:2cm);

    \draw (top.35) -- ++(90:1cm);
    \draw (top.60) -- ++(90:1cm);
    \node at (-.1,1.2) {...};
    \draw (top.145) -- ++(90:1cm);

    \draw (bottom.-35) -- ++(-90:1cm);
    \draw (bottom.-60) -- ++(-90:1cm);
    \node at (-.1,-1.2) {...};
    \draw (bottom.-145) -- ++(-90:1cm);
\end{tikzpicture}
-
\frac{\qi{2}}{\qi{2n-1}}
\begin{tikzpicture}[baseline]
    \clip (-1,-2.2) rectangle (2.5,2.2);

    \node at (.5,0) (JW) [rectangle, draw] {$ \JW{4n-4}$};
    \node at (0,-1.6) (bottom2) [ellipse,draw]{$ \hspace{.15 cm} S \hspace{.15cm} $};
    \node at (0,1.6) (top2) [ellipse,draw]{$ \hspace{.15 cm} S \hspace{.15cm} $};
        \node at (top2.0) (invisible) [right] {};
    \node at (bottom2.0) (invisible2) [right] {};
    \filldraw (top2.180) circle (.5mm);
    \filldraw (bottom2.180) circle (.5mm);    

    \draw (JW.35) arc (180:0:.2cm) -- ++(-90:.7cm) arc (0:-180:.2cm) --(JW.-35);
    \node at (JW.75) [above] {...};
        \node at (JW.-75) [below] {...};
    \draw (JW.135) arc (180:0:1cm) -- ++(-90:.7cm) arc (0:-180:1cm) --(JW.-135);
        \draw (invisible.90)--++(90:1cm);
    \draw (invisible.90) .. controls ++(-90:6mm) and ++(90:10mm) .. (JW.145);
    \draw (invisible2.-90)--++(-90:1cm);
    \draw (invisible2.-90) .. controls ++(90:6mm) and ++(-90:10mm) .. (JW.-145);

    \draw (top2.35) -- ++(90:1cm);
    \draw (top2.60) -- ++(90:1cm);
    \node at (-.1,2.1) {...};
    \draw (top2.145) -- ++(90:1cm);

    \draw (bottom2.-35) -- ++(-90:1cm);
    \draw (bottom2.-60) -- ++(-90:1cm);
    \node at (-.1,-2.1) {...};
    \draw (bottom2.-145) -- ++(-90:1cm);
\end{tikzpicture}\\
