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

// Induced graph on cells.
#0:.
#1:->#0.
#2:->#0.
#3:->#1,#2.

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

// cell #1:
0[1]: {3,4}

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

// cell #3:
0[3]: {1,2,3,4}