Removed Theorem 1.16 (the count formula for spoke-only and
single-chord cases). Folded the cycle formula 2^n + 2(-1)^n into
the surviving remark so the only retained content is the structural
observation:
- Tait reduces 4-coloring count to 3-edge-coloring count of Γ.
- For Γ ≅ C_n (spoke-only): cycle chromatic polynomial gives
2^n + 2(-1)^n.
- For Γ with chords, the count depends on chord structure
(nested vs. sequential etc.), not just (n, k).
- Always computable in linear time via tree decomposition
(outerplanar has treewidth ≤ 2).
Page count: 12 → 11.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
didericis
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