SAT proof storage

color509.drat and color509.core.drat are not in the git tree. The graph is 509_parts.vtx. The coloring summary is color509.json (UNSAT, triangle (0,149,152)).

Regenerate the 4-coloring proof

python3 -m venv .venv && .venv/bin/pip install sympy python-sat
.venv/bin/python color_sat.py 509_parts.vtx --proof color509.drat

Then ./run_verify.sh rebuilds the unit-distance graph and, if color509.drat is present, checks it with drat-trim against a fresh CNF. Without the DRAT, run_verify.sh still checks the 509 vertices / 2442 edges and stops there.

There is no Release URL for the old proof files.