Counterexample CE-DS-LCM-SIGNSPLIT-MINIMAL-001

What it falsifies

None: support-minimal atomic boundary witness for the (M5)-free sign-split mechanism; it is not a counterexample to DS17, whose population obstruction assumes atomlessness and (M4), and whose empirical conclusion assumes (M5).

CE-DS-LCM-SIGNSPLIT-MINIMAL-001: labels before, 3 atoms in 3 cells-1-0.50000.5001-1012score 1score 2
Labels before
CE-DS-LCM-SIGNSPLIT-MINIMAL-001: labels after / optimum, 3 atoms in 3 cells-1-0.50000.5001-1012score 1score 2
Labels after / optimum
  • Cell 0
  • Cell 1
  • Cell 2
Atoms of CE-DS-LCM-SIGNSPLIT-MINIMAL-001
AtomWeightScore 1Score 2Cell beforeCell after
11/3-1100
21/3-1-111
31/32022

Objective

The criterion value at each labelling, exactly as the fixture certifies it.

LabellingObjective
Labels before2
Labels after2

How it was verified

Method: exact_formula.

Recompute all moments in fractions.Fraction. Exact centering gives I_q=diag(2,2/3), B*_q=0, projected centroids (-1,-1,2), and the merged two-cell rule has zero nuisance block.

Claims that cite it

Recorded 31 August 2026. The fixture as JSON.