2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/110065I prefer taking off this paper for the moment because of a mistake in the lemma 2.1 of the secund version. Precisely, in the proof of this lemma, it is not clear that the morphism $r\_j$ is flat, that I claim it.This paper has been withdrawnRepresentation Theorytext