digraph Test {
    splines = ortho;
    nodesep = 1.0;
    ranksep = 1.0;
    edge [dir = both, arrowhead = vee, arrowtail = inv,
          labelangle = 60, labeldistance = 2.2, headlabel = "Head", taillabel = "Tail"];
    A -> B;
    A -> C;
    D -> C;
}
