monotonicity_test.py inserts interior vertices and checks |Phi|. Degree-3
stacks preserve Phi exactly (confirms un-stacking, 100%), but degree-4
insertions can SHRINK Phi (6->5, 30->28) and Phi(D') subset Phi(D) fails
~13% -- so the reduce-to-base-case proof of the 2^(n-2) floor via
monotonicity does not work. Violations stay above the floor, so the floor
is protected by something stronger; redirect to a direct n-2 toggle
construction.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
didericis
9f6328788c