didericis 56ebf49b48 coloring_nested_tire_graphs: rainbow theorem proof (sharp threshold + 2-SAT reduction)
Replaces the earlier proof sketch with a clearer attempt that:

1. Corrects the sharp threshold: m_1 >= m - 1 (not m_1 >= m).
   Empirically verified for m ∈ {4, 6} across m_1 ≥ m - 1.

2. Proves the ⊆ direction cleanly: each O-face dual vertex has
   degree m/2 ≤ 3 in T'_{f'}, so its incident spokes must be
   pairwise distinct, putting σ in the "perms-per-half" set P_m.

3. Reduces the ⊇ direction to a cyclic 2-SAT solvability claim
   (Conjecture 2sat): for each σ ∈ P_m, find an "orientation"
   o ∈ {0,1}^m at the m D-positions such that each length-1 gap
   has R_j = L_{j+1} and each length-2 gap has R_j ≠ L_{j+1}.

4. Acknowledges the gap: a naive "all-zero orientation" fails
   (e.g. rainbow at m_1 = 6 has the all-zero attempt fail at
   gap (4,5)).  A satisfying assignment exists in every tested
   case (6-18 per σ at m=6, m_1=6) but a clean general proof
   awaits.  Two routes outlined: S_3-equivariant case analysis,
   or global implication-graph analysis.

5. Confirms sharpness with explicit forcing-propagation
   counterexample at m=6, m_1=4 (rainbow not in π_D).

6. States provisional corollary: π_D = P_m at m_1 ≥ m - 1
   (conditional on Conjecture 2sat); chain pigeonhole reduces
   to π_U meeting P_m.

Honest about what's proven (the ⊆ half, the 2-SAT reduction,
the sharpness counterexample) and what's left (the 2-SAT
solvability proof).

Note: rainbow_proof.tex (4 pages).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 04:18:00 -04:00
2026-04-12 22:23:55 -04:00
2026-04-20 16:32:27 -04:00
2026-04-20 16:32:27 -04:00
2026-04-20 17:00:04 -04:00
2026-04-20 16:32:27 -04:00
2026-04-17 00:54:42 -04:00
2026-05-09 11:34:58 -04:00

math-research

Personal mathematics research repository by Eric Bauerfeld. Papers are written in AMS-LaTeX using the amsart document class.

Papers

kempe_style_search_for_smaller_contradiction

Humans Suffice: A Novel Proof of the Four Color Theorem

An in-progress proof of the Four Color Theorem via a minimal counterexample argument. The paper builds on Kempe's 1879 strategy — establishing valid cases for vertices of degree ≤ 4, then extending the argument to the degree-5 case using properties of non-adjacent degree-5 vertices, merged subgraphs, and locked colorings.

plane_depth_labelling

Plane Depth Labelling

Early-stage paper. Title and author information set; content in progress.

Creating a New Paper

Use run.sh to scaffold a new paper from the AMS-LaTeX template:

./run.sh init_paper "Your Paper Title"

This creates a new directory (name derived from the title) containing a paper.tex pre-filled with the title and author.

Setup

The Python library code in lib/ requires SageMath. Run setup once per machine:

./run.sh setup <sage_python_path> <sage_site_packages> [system_name]
  • sage_python_path — path to the SageMath Python interpreter (e.g. /opt/sage/local/bin/python3)
  • sage_site_packages — path to SageMath's site-packages directory
  • system_name — optional label for this machine (defaults to hostname -s); used to store per-machine env files as .env.<system_name>

On subsequent runs the paths default to whatever was saved in .env, so ./run.sh setup alone re-runs setup with the existing configuration.

Setup also compiles the plantri submodule via make.

Running Sage

To run a Sage script with plantri available on PATH:

./run.sh sage <script.py> [args...]

Or to open an interactive Sage session:

./run.sh sage

Linting

./run.sh lint

Runs pyright and pylint on lib/ using the SageMath Python interpreter.

Shell Completion

To enable tab-completion for run.sh in zsh, add this to your .zshrc:

eval "$(path/to/run.sh completion)"

Or source it once in the current shell session:

eval "$(./run.sh completion)"

Building

Papers are compiled with LaTeX. From within a paper directory:

latexmk -pdf paper.tex
S
Description
No description provided
Readme 277 MiB
Languages
Python 69%
TeX 30.8%
Shell 0.2%