\begin{tikzpicture}[x=1ex,y=1ex,baseline={([yshift=-.5ex]current bounding box.center)}]
    \coordinate (v);
    \coordinate[left=1 of v] (v1);
    \coordinate[right=1 of v] (v3);

    \draw (v1) to (v3);
    \filldraw (v1) circle(1pt);
    \filldraw (v3) circle(1pt);

    \coordinate [right=.7 of v3] (v12);
    \draw (v12) circle(.7);
    % \filldraw (vm2) circle (1pt); 

\end{tikzpicture}%