didericis c8ddbb5d9f coloring_nested_tire_graphs: prove outer-triangle absorption via K_3-walk parity invariant
Investigation of the 'outer triangle absorption' hypothesis from
notes/outer_triangle_absorption.tex:

H2 (T_n alone absorbs anything to 6 perms): REFUTED. T_n=(3,k) alone
has σ_U-projection equal to all 27 elements of {1,2,3}^3.

H1 (chain does real work): TRUE, and structurally explained:

  K_3-walk parity invariant (Lemma): in any proper edge 3-coloring
  of C_n viewed as a closed walk in K_3, the 3 edge-traversal counts
  all have the same parity (follows from each vertex's walk-degree
  being even).

  σ-color count parity (Corollary): σ at the full n cycle positions
  has all-same-parity color counts.

  Chain preserves parity (Theorem): forward propagation through SR
  tire T=(m,k) maps state with parity matching k to state with parity
  matching m, via σ_U + σ_D = σ_total with parities adding mod 2.

  Outer-triangle absorption (Main Theorem): at L_n with |L_n|=3,
  state has all-odd color counts summing to 3, forcing each count =
  1, i.e., σ is a permutation of {1,2,3}.

Empirically verified: 0 parity violations across all chain states
in 3 representative chains (sizes 30-14643).

What's left:
  - Non-emptiness: state at L_n EQUALS (not just ⊆) the 6 permutations.
    Empirically yes. Likely via S_3-invariance argument.
  - SR-correctness for actual G (the modeling gap, not addressed here).

If non-emptiness and SR-correctness are closed, this is a structural
proof of 4CT under the PDS framework — fundamentally different from
Birkhoff/Heesch reducibility.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 12:42:28 -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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