2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/100093This paper has been withdrawn by the author. The central result is now included in quant-ph/0309056 (as in the journal publication!). An erratum on the Heisenberg perturbation series estimate is also included therein.This paper has been withdrawn by the authorQuantum Physicstext