The question

A35 §2 of the exchange of 2026-10-17 sorted five diagnostics by their expected invariance. The first three are about charts of one parameter space, and this question asks about those three.

The answer

CLAIM-366, Active, proves all three rows:

  • Common strict first-order descent (0 ∉ conv{g_i}) is invariant under smooth invertible reparameterization. The chart’s Jacobian is invertible, so it maps the descent cone of one chart onto that of the other.
  • The sign of a Euclidean gradient inner product is not invariant. A negative inner product does not exclude common descent.
  • Budgeted feasibility is invariant once the update geometry is pulled back along the change of chart.

The other two rows, function-preserving symmetries and finite-step trajectories, are not changes of chart, and they remain QUESTION-127’s.