diff --git a/papers/medial_tire_decompositions_of_plane_triangulations/experiments/chained_seam_findings.md b/papers/medial_tire_decompositions_of_plane_triangulations/experiments/chained_seam_findings.md index b79efd8..5f8e5d6 100644 --- a/papers/medial_tire_decompositions_of_plane_triangulations/experiments/chained_seam_findings.md +++ b/papers/medial_tire_decompositions_of_plane_triangulations/experiments/chained_seam_findings.md @@ -169,11 +169,35 @@ Branching tile = `≥2` inner faces carrying singleton-down interfaces (a tree n So **n=14** is the smallest place to test the uniform family / `R_T` composition on a genuine *branching* no-separating-triangle tile — the conjecture's real case. +## Finding 7 — the branching case (n=14) is FEASIBLE with one regular family + +Full uniform-family CSP at n=14 `--no-tri` (4403 tiles, 3766 bite, **193 branching**): +**FEASIBLE** — a single uniform family threads every tile, branching nodes included +(each branching tile shows the uniform state on its outer rim AND both inner faces at +once). Domains `|D[m]|`: `4:2 5:1 6:2 7:2 8:3 9:3 10:5`. The witness family is fully +regular: + +``` +σ_m = 0^m (monochromatic) if m even +σ_m = 0^(m-2) 1 2 (one block + 1 + 2) if m odd + 4:0000 5:00012 6:000000 7:0000012 8:00000000 9:000000012 10:0000000000 +``` + +A direct candidate test (just the 193 branching tiles) confirmed it independently: +the monochromatic-even / min-cut-odd family threads **193/193**. + +So on the 4CT-relevant class (no separating triangles), the chained-seam pigeonhole is +**constructively resolved throughout the tested range** (n = 9, 12, 14, including the +first branching nodes) by one explicit regular seam family: paint every even level +cycle one colour, and every odd level cycle as a single monochromatic block plus the +two parity-forced off-colour vertices. + ## Open threads -- **Test the uniform family at n=14 (restricted).** The first branching tiles live - here; does `monochromatic-even / min-cut-odd` still thread them (now with 2 inner - faces forced simultaneously)? This is the genuine conjecture case. -- **Does the restricted uniform family persist past n=13?** A single later failure - (as in the unrestricted n=12 case) would be very informative. -- **`R_T` composition along real trees** rather than per-size uniformity. +- **Conjecture the regular family always works.** Does `σ_m = 0^m` (even) / + `0^{m-2}12` (odd) thread *every* no-separating-triangle tile for all `n`? Push to + n=15, 16 (branching grows: 1022 branching tiles at n=15) and look for any failure. +- **Why does the restriction make monochromatic-even universal?** Separating-triangle + tiles are exactly what blocked an all-one-colour rim; removing them frees it. +- **`R_T` composition along real trees** rather than per-size uniformity — the fully + general conjecture.