files / problems / ramsey-r55 / compute / q7 / README.md

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R(5,5) / leftover 2/3/5 SAT

No endpoint moved. The published interval remains 43≤R(5,5)≤4643\le R(5,5)\le 46.

Exact finite results

No new independently replayed certificate. The encoder is q2's orbit_sat.py, unchanged.

kissat --unsat --seed=17 printed s UNSATISFIABLE for 551185^5 1^{18} at k=1k=1 in 7575s. The trimmed DRAT is 3.9GB. That is over GitHub's blob limit, so the proof is not stored. The independent check of the trimmed file was stopped at wrap. Hashes and sizes are in certs/p5_c5_k1.json. This is not a restriction you can replay from the repo.

Together with q2, q3, q4, q5, and q6, a hypothetical (5,5,43)(5,5,43)-graph can have automorphism-group order with prime divisors only among 2, 3, and 5, and if 5 divides that order then the permutation is not of type 565^6 or 575^7, is not of type 545^4 with a fixed vertex meeting 0 or 4 of the 5-cycles, and is not of type 555^5 with a fixed vertex meeting 2 or 3 of the 5-cycles. This is a restriction on a hypothetical graph, not a bound on R(5,5)R(5,5).

Searches still incomplete

551185^5 1^{18} at k=1k=1 has no stored proof. 521335^2 1^{33} at k=2k=2 and 312173^{12}1^{7} at k=5k=5 timed out at sixty minutes. 531285^3 1^{28} at k=3k=3, 3111103^{11}1^{10} at k=5k=5, and 220132^{20}1^{3} at k=10k=10 were stopped mid-run. The five maximum-cycle order-2/3/5 representatives and the rest of the leftover 2/3/5 list are unfinished. These timeouts imply no further restriction.

No (5,5,43)(5,5,43)-graph was decoded.

Replay

The Python scripts need python-sat. The solver and checker are the pinned q2 builds: kissat 4.0.4 at commit 8af8e56f174b778aef3aa45af9f739b2a5f492c2 and drat-trim at commit 2e3b2dc0ecf938addbd779d42877b6ed69d9a985.

python3 -m venv .venv
.venv/bin/pip install python-sat
../q2/build_tools.sh
./run_all.sh

There is no stored DRAT. run_all.sh regenerates the leftover case list and writes certs/q7_summary.json. Collected result: certs/q7_summary.json.