// Cells and their vertices.
#0={0}
#1={1,2,3,4,5,6,7,8}

// Induced graph on cells.
#0:.
#1:->#0.

// Individual cells.
// cell #0:
0[0]: {}

// cell #1:
0[1]: {1} --> 1
1[2]: {2} --> 0,2
2[3]: {3} --> 1,3
3[4]: {4} --> 2,4
4[5]: {5} --> 3,5
5[6]: {6} --> 4,6,7
6[7]: {7} --> 5
7[8]: {7} --> 5