Computes a single nice layout for the full G' (Holton-McKay #0) by
trying sage-planar, sage-spring, and networkx-planar layouts and
picking the one with smallest edge-length coefficient of variation.
Spring layout wins (CV^2 = 0.049).
Then uses the SAME positions for G'_0 and G'_1, with pendant
vertices placed offset from their boundary vertex in the direction
of their cut-edge neighbor. This makes the visual correspondence
between G' and its two halves immediate.
Layout: 3 vertical panels showing G' (with cut edges highlighted),
G'_0, G'_1. Each subgraph draws only its own vertices (no orphan
vertices from the other side); all three share the same x-y limits
so positions align across panels.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
didericis
d065c5c31b