didericis 96102e6d03 coloring_nested_tire_graphs: examine chain pigeonhole on cut tires
New note cut_tire_chain_pigeonhole.tex (3 pages) walking through the
chain pigeonhole argument applied to the cut-tire framework:

Setup: minimum counterexample G' to 4CT, 6-edge cut splits into
G'_0, G'_1, depth labelling gives chains of cut tires on each side.

Argument shape:
  (1) Minimality ⇒ both G'_i have proper 3-edge-colorings.
  (2) Restrict to depth-0 pendants → boundary configurations σ_0, σ_1.
  (3) Glue iff σ_0 = σ_1; counterexample ⇒ no such matching.
  (4) Layered description: each cut tire has inner/outer projection
      constraints; adjacent tires share layers (outer of T_d =
      inner of T_{d+1}).
  (5) Chain pigeonhole: if each π_in is "large enough,"
      R_0 ∩ R_1 ≠ ∅, contradiction.

What this needs to be a proof:
  (a) Chain well-definedness: each H_d has ≥ 1 face, adjacencies
      clean, no degenerate cases.
  (b) Quantitative chain pigeonhole at each layer (= the rainbow
      conjecture or König-lift conjecture from existing notes).
  (c) Cut-tire-specific issues: H_d not cubic, face boundaries may
      not be simple cycles, transfer of primal-tire results requires
      verification.

Empirical chain on G'_1 of Holton-McKay #0: chain length 7,
irregular face structure across depths.  No counterexample yet but
no proof either.

Net assessment: structurally sound reformulation, but inherits all
open conjectures from the existing approaches plus new technical
issues.

Concrete next step: extend tire_fiber_step2-style pairwise compatibility
check to the cut-tire setting and see if R_0 ∩ R_1 = ∅ empirically
on the Holton-McKay graphs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 15:37:14 -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
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