// Cells and their vertices.
#0={0,1,2}
#1={3}

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

// Individual cells.
// cell #0:
0[0]: {2} --> 2
1[1]: {2} --> 2
2[2]: {1} --> 0,1

// cell #1:
0[3]: {1,2}