\begin{tikzpicture}[auto,scale=\rtree,transform shape]
	% x node set with absolute coordinates
	\node (i1) at (0,0) [label=left:$i_1:f_D(DBC)$,point];
	\node (i2) at (2,0) [label=right:$i_2:f_B(BA)$,point];
	\node (i3) at (1,1.3) [label=right:$i_3$,point];
	\node (i4) at (0,1.3) [label=left:$i_4:f_C(CA)$,point];
	\node (i5) at (1,2.6) [label=right:$i_5$,point];
	\node (i6) at (2,2.6) [label=right:$i_6:f_F(FDE)$,point];
	\node (i7) at (1,3.9) [label=left:$i_7$,point];
	\node (i8) at (0,3.9) [label=left:$i_8:f_E(EBC)$,point];
	\node (i9) at (1,5.2) [label=right:$i_9$,point];
	\node (i10) at (2,5.2) [label=right:$i_{10}:f_C(CA)$,point];
	\node (i11) at (1,6.5) [label=left:$i_{11}$,point];
	\node (i12) at (0,6.5) [label=left:$i_{12}:f_B(BA)$,point];
	\node (i13) at (1,7.8) [label=right:$i_{13}$,point];
	\node (i14) at (1,9.1) [label=right:$i_{14}:f_A(A)$,point];
	
	\path (i1) edge node[left] {$DBC$} (i3);
	\path (i2) edge node[right] {$BA$} (i3);
	\path (i3) edge node[right] {$DC\bcancel{B}A$} (i5);	
	\path (i4) edge node[left] {$CA$} (i5);
	\path (i5) edge node[left] {$D\bcancel{C}\bcancel{B}A$} (i7);
	\path (i6) edge node[right] {$ED$} (i7);
	\path (i7) edge node[right] {$E\bcancel{C}\bcancel{B}A$} (i9);	
	\path (i8) edge node[left] {$ECB$} (i9);
	\path (i9) edge node[left] {$CBA$} (i11);	
	\path (i10) edge node[right] {$CA$} (i11);	
	\path (i11) edge node[right] {$BA$} (i13);
	\path (i12) edge node[left] {$BA$} (i13);
	\path (i13) edge node[right] {$A$} (i14);
	%\node (i1) at (0,0) [label=left:$i_1(C_1|X)$,point];
	%\node (i2) at (3,0) [label=right:$i_2(X|A)$,point];
	%\node (i3) at (1.5,0) [label=below:$i_3$,point];
	%\node (i4) at (1.5,1.5) [label=right:$i_4$,point];
	%\node (i5) at (0,1.5) [label=left:$i_5(D|C_1C_2)$,point];
	%\node (i6) at (1.5,3) [label=left:$i_6$,point];
	%\node (i7) at (3,3) [label=right:$i_7(C_2|X)$,point];
	%\node (i8) at (1.5,4.5) [label=above:$i_8$,point];
	%\node (i9) at (3,4.5) [label=right:$i_9(A)$,point];
	%\node (i10) at (0,4.5) [label=left:$i_{10}(X|A)$,point];
	
	% Directed edge
	%\path (i1) edge node[below] {$C_1X$} (i3);
	%\path (i2) edge node[below] {$XA$} (i3);
	%\path (i3) edge node[right] {$\bcancel{X}C_1A$} (i4);
	%\path (i4) edge node[below] {$C_1C_2$} (i5);
	%\path (i4) edge node[left] {$\bcancel{X}C_2A$} (i6);
	%\path (i6) edge node[above] {$XC_2$} (i7);
	%\path (i6) edge node[left] {$XA$} (i8);
	%\path (i8) edge node[above] {$XA$} (i10);
	%\path (i8) edge node[above] {$A$} (i9);
	%\draw[dotted] (p) -- (ep);
	%\draw[dotted] (c) -- (ec);
	% Bidirected edge
	%\path[bidirected] (A) edge[bend left=60] (C);
	%\node at ($(1)!.5!(2)$) {\ldots};
\end{tikzpicture}
