didericis 203b005336 coloring_nested_tire_graphs: chain half analysis + tree DP empirical test
NEW NOTE: chain_half_analysis.tex (4 pages).

Formulates the chain half of the loose conjecture as a tree DP
over the cut tire forest, identifies what's proven vs. open:

PROVEN
- Tree structure (high-side forest): from
  cut_tire_tree_structure.tex
- S_3-equivariance of the DP: trivial Lemma in this note
- Per-tire half for spoke-only cut tires (n ≥ 3): Prop 1.13

OPEN / GAPS DISCOVERED
1. Cut tires are NOT in general spoke-only. H_d can have degree-3
   vertices (= branch points), making face boundaries non-simple
   cycles.  Dodecahedron 6-edge cut yields H_1 with one face of
   length 20 over only 11 distinct vertices.  Prop 1.13's count
   2^n + 2(-1)^n applies only to spoke-only tires.

2. OUT-only projection loses S_3 orbit info.  The per-tire half
   guarantees a full S_3 orbit on the JOINT (in + out) projection,
   but restricting to OUT spokes can collapse to |A|=3 (constant
   tuples). Empirically observed ~20% of the time on test cases.
   Correct DP must track joint projection (analog of
   tire_fiber_step2.tex's joint-support tracking).

3. Non-emptiness preservation through the DP is the genuine open
   piece (Conj. in this note + Strong per-tire extendibility).

EMPIRICAL TESTS
- chain_dp_test.py: simple cycle DP (assumes spoke-only).
- chain_dp_general.py: handles branched faces via brute-force
  3-edge-coloring enumeration (cut off at 12 edges/tire for
  tractability).
- chain_dp_debug.py: diagnostic for inspecting H_d face structure.

The general test reveals all three gaps above when run on
Dodecahedron + HM #0.  Cross-cut R_0 ∩ R_1 should be non-empty
for both (they are 3-edge-colorable), but the heuristic
parent-finding plus OUT-only projection produce false negatives.

Status table at end of note summarizes what's needed to close.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 22:49:20 -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%