Incidence matrix
xq ox&#q faceting
2 * | 1 2 2 0 0 0 | 2 2 1 0
* 4 | 0 1 1 1 1 1 | 1 2 1 1
----+-------------+--------
2 0 | 1 * * * * * | 2 0 0 0 x : ef
1 1 | * 4 * * * * | 1 1 0 0 q : ae,be,cf,df
1 1 | * * 4 * * * | 0 1 1 0 w : af,bf,ce,de
0 2 | * * * 2 * * | 0 0 1 1 x : ab,cd
0 2 | * * * * 2 * | 1 0 0 1 q : ad,bc
0 2 | * * * * * 2 | 0 2 0 0 h : ac,bd
----+-------------+--------
2 2 | 1 2 0 0 1 0 | 2 * * * verf(sirco)
1 2 | 0 1 1 0 0 1 | * 4 * * verf(girco)
1 2 | 0 0 2 1 0 0 | * * 2 * verf(tic)
0 4 | 0 0 0 2 2 0 | * * * 1 verf(co)