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ramsey-cells

Colorings for small graph Ramsey cells, with the encoder, an independent checker, and the scripts that redo the work. Unconfirmed, not peer reviewed. Nothing here is a claim.

cell DS1 rev #18 deposited
R(K_{2,10}, K_{2,7}) 29-31 K_30 k2x10-k2x7-lb31/
R(K_{2,10}, K_{2,6}) 27-29 K_28 k2x10-k2x6-lb29/
R(K_{2,2}, K_{2,19}) 28/29 K_28 k2x2-k2x19-lb29/
R(K_{2,11}, K_{2,4}) >= 25 K_25 k2x11-k2x4-lb26/
R(K_{2,11}, K_{2,6}) >= 29 K_29 k2x11-k2x6-lb30/
R(K_{3,5}, K_{2,5}) 21-23 K_21 k35k25-lb22/
R(B_5, B_9) >= 28 K_28 b5b9-lb29/
R(K_{3,4}, K_{3,3}) 19-20 refutation at n=19 k34k33-n19/
R(K_{3,5}, K_{2,4}) 19-20 K_18 + refutation at n=19 k35k24-n19/

A coloring of K_n gives R > n. Checking one needs only the definition of subgraph containment. The refutation needs more: a faithful encoding, sound symmetry breaking, and an exhaustive search. Each directory says which parts are machine-checked.

See NOTICE.md — the K_18 coloring in k34k33-n19/ is Van Overberghe's.

Check

python3 tools/check_ramsey.py k2x10-k2x7-lb31/witness/witness_k2x10k2x7_n30.txt K2x10,K2x7

Or open bench.html and paste any coloring. It shares no code with the encoder.

tools/ has three checkers, each written from the definitions: check_ramsey.py (complete bipartite and cliques), check_book.py (books B_t), check_mixed.py (both).

Each witness declares its own parameters:

# spec: K3x5,K2x5
# name: K(3,5)/K(2,5) on K21

python3 tools/gen_views.py regenerates every matrix, SVG and bench.html from the witnesses. The witnesses are the artifacts; everything else is derived.

About

Computation records for small graph Ramsey cells: formulas, cube decompositions, verdict ledgers, and reconstruction scripts. Unconfirmed, not peer reviewed.

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