=== Generalization of the proof ===This applies to "any" local symmetry derivation "Q" satisfying "QS" ≈ 0, and also to more general local functional differentiable actions, including ones where the Lagrangian depends on higher derivatives of the fields.
=== Generalisation of the proof ===This applies to "any" derivation Q, not just symmetry derivations and also to more general functional differentiable actions, including ones where the Lagrangian depends on higher derivatives of the fields and nonlocal actions.