Commit Graph

7 Commits

Author SHA1 Message Date
didericis 41bbe40c32 Frame the 4-coloring motivation and add an online greedy check
Adds a Motivation section to paper.tex explaining that the
quadrilateral sequencing is intended to support an inductive 4-coloring
of the underlying maximal planar graph, with ring completion as the
suspected obstacle.

Adds commentary.tex recording (a) why a pure pigeonhole argument is
unlikely to close the conjecture, (b) the observation that under any
strictly local online rule every G'-edge constraint is enforced when
its second endpoint is colored (so ring completions cannot fail at the
moment they fire), and (c) the empirical finding that pure greedy
fails at non-ring-completion moves on every 3-connected triangulation
of order 5-7.

Adds quad_sequence_coloring_check.py, an enumeration check over small
triangulations via Sage's planar_graphs that runs greedy online
4-coloring under the canonical sequence and classifies failures.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-15 03:05:44 -04:00
didericis 83914a6a20 Draft quadrilateral sequencing section
Extend the deep embedding to include the outer face, decompose into
quadrilaterals via level-edge pairing on the sphere, and define a
deterministic sequence built from four moves (anchor drop, level add,
join, ring completion) with a recursive lex-smallest tiebreak on the
initial quadrilateral. Attempt the termination theorem and the per-move
case analyses.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-15 02:04:21 -04:00
didericis 927f9b7adb Simplify d=0 case in outerplanar lemma proof
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-25 05:22:25 -04:00
didericis 5605e035d3 Add outerplanar lemma with Baker citation and relate depth levels to k-outerplanar graphs
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-25 04:39:28 -04:00
didericis 47d260b1b9 Add neutral triangle definition and use up/down/neutral triangle terms in lemma
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-25 04:15:36 -04:00
didericis fe423dc7ba Add level edge definition to plane depth sequencing paper
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-25 04:08:33 -04:00
didericis 9e3e525a5b Replace plane_depth_labelling with plane_depth_sequencing paper and script, remove unused lib modules
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-24 21:10:06 -04:00