Counterexample · A-FINITE-GEOMETRY-FAILS
A stability does not force geometry
Counterexamplepublication: internal
Meaning
A counterexample prevents transferring the finite D exchange-to-geometry theorem to A.
Statement
Finite exchange stability does not generally collapse to the first-order I^{-2} Voronoi assignment rule.
Where it stops
Refuted by
- CE-A-DSTYLE-001
The D exchange-to-geometry mechanism transfers to the A criterion: a move whose first-order I_q^{-2} Mahalanobis margin is positive (row strictly closer to the destination centroid in the I^{-2} metric) must not decrease the exact A objective -tr(I_q^{-1}).
Relationships
Enables
- Quantitative A finite-geometry necessity boundOPEN-A-QUANTITATIVE-BOUND
- Characterize criteria with finite exchange => first-order geometryOPEN-CRITERION-CHARACTERIZATION
Raises
Open next door
Local graph
The example
A2. D-style finite geometry theorem fails
The reported search found 443 A moves violating the would-be D-style implication. Therefore finite exchange stability does not generally collapse to the first-order Voronoi rule.
From A-optimality · chapter contents
Evidence: COUNTEREXAMPLES/CE-A-DSTYLE-001.json. Measured, never theorem authority.