dot graphs for "Maintaining an efficient ordering where you can insert elements “in between” any two other elements in the ordering?" at http://cs.stackexchange.com/a/14710/2755

list.1.dot

#step 1
digraph list{

  {rank=same;
    D1[style=invis,shape=point];
    D1[style=invis];
  }

  {rank=same;
    D[dir=back];
  }
  
  D1 -> D;
}

list.2.dot

#step 2
digraph list{

  {rank=same;
    C1[style=invis,shape=point];
    D1[style=invis,shape=point];
    C1 -> D1[style=invis];
  }

  {rank=same;
    C -> D[dir=back];
  }

  C1 -> C;
}

list.3.dot

#step 3
digraph list{

  {rank=same;
    A1[style=invis,shape=point];
    C1[style=invis,shape=point];
    D1[style=invis,shape=point];
    A1 -> C1 -> D1[style=invis];
  }

  {rank=same;
    A -> C[dir=back];
    C -> D[dir=back];
  }

  A1 -> A;
}

list.4.dot

#step 4
digraph list{

  {rank=same;
    A1[style=invis,shape=point];
    B1[style=invis,shape=point];
    C1[style=invis,shape=point];
    D1[style=invis,shape=point];
    A1 -> B1 -> C1 -> D1[style=invis];
  }

  {rank=same;
    A -> B[dir=back];
    B -> C[dir=back];
    C -> D[dir=back];
  }

  B1 -> B;
}

list.5.dot

#step 5
digraph list{

  {rank=same;
    A1[style=invis,shape=point];
    B1[style=invis,shape=point];
    C1[style=invis,shape=point];
    D1[style=invis,shape=point];
    E1[style=invis,shape=point];
    A1 -> B1 -> C1 -> D1 -> E1[style=invis];
  }

  {rank=same;
    A -> B[dir=back];
    B -> C[dir=back];
    C -> D[dir=back];
    D -> E[dir=back];
  }

  E1 -> E;
}

list.6.dot

#step 6
digraph list{

  {rank=same;
    A1[style=invis,shape=point];
    B1[style=invis,shape=point];
    C1[style=invis,shape=point];
    F1[style=invis,shape=point];
    D1[style=invis,shape=point];
    E1[style=invis,shape=point];
    A1 -> B1 -> C1 -> F1 -> D1 -> E1[style=invis];
  }

  {rank=same;
    A -> B[dir=back];
    B -> F[dir=back];
    F -> C[dir=back];
    C -> D[dir=back];
    D -> E[dir=back];
  }

  F1 -> F;
}

tree.1.dot

#step 1
digraph tree{

  D;

}

tree.2.dot

#step 2
digraph tree{


  D -> C;

  
  D -> D1[style=invis]; D1[style=invis];

}

tree.3a.dot

#step 3
digraph tree{


  D -> C;
  D -> D1[style=invis]; D1[style=invis];

  C -> A;
  C -> C1[style=invis]; C1[style=invis];
}

tree.3b.dot

#step 3, rotation
digraph tree{


  C -> A;
  C -> D;
}

tree.4.dot

#step 4
digraph tree{


  C -> A;
  C -> D;

  A -> A0[style=invis]; A0[style=invis];
  A -> B;
  
}

tree.5.dot

#step 5
digraph tree{


  C -> A;
  C -> CAD0[style=invis]; CAD0[style=invis];
  C -> D;

  A -> A0[style=invis]; A0[style=invis];
  A -> B;
  
  D -> D0[style=invis]; D0[style=invis];
  D -> E;
}

tree.6a.dot

#step 6
digraph tree{


  C -> A;
  C -> CAD0[style=invis]; CAD0[style=invis];
  C -> D;

  A -> A0[style=invis]; A0[style=invis];
  A -> B;
  
  D -> D0[style=invis]; D0[style=invis];
  D -> E;


  B -> B0[style=invis]; B0[style=invis];
  B -> F;
}

tree.6b.dot

#step 6, rotation
digraph tree{


  C -> B;
  C -> CAD0[style=invis]; CAD0[style=invis];
  C -> D;

  B -> A;
  
  D -> D0[style=invis]; D0[style=invis];
  D -> E;


  B -> F;
}