2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/139486This paper has been withdrawn by the author due to an error in Lemma 3, making the (bijective) proof of Theorem 4 and Corollary 5 invalid (symmetry of k-nonnesting and k-noncrossing set partitions).This paper has been withdrawnCombinatorics05A18 (Primary); 05A30, 05A15 (Secondary)text