Cube index for exact Caccetta–Häggkvist triangle orders from n=38
through n=72. The DRAT bytes are not in the git tree; see
../../STORAGE.md.
A d-outregular oriented graph has n d arcs, so some in-degree is
at least d. Relabel that vertex as 0. The exact statement reduces
to cubes k=|N⁻(0)| ≥ d. Each cube was UNSAT with a DRAT. Local
replay regenerates the CNF from encode.py and checks a
regenerated proof; do not trust leftover certs/*.cnf scratch
files.
cd problems/caccetta-haggkvist-k3/compute/q3
./build_solvers.sh
./run_all.sh
Orders stored: 38, 39, 41, 42, 44, 45, 47, 48, and 50 through 72.
The n ≡ 1 (mod 3) values 40, 43, 46, 49 are already implied by
HKN 0.3465. The index is replay.json after a successful
verify_keep.py. Circulant soundness (cyclic degree, not a
counterexample) is soundness_n38_d12.json.