// Cells and their vertices. #0={0} #1={1,2,3,4} // 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]: {4,5} --> 2