2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54769We report on recent advances in the understanding of non-perturbative phenomena in the quantum theory of fields and strings.6 pages, latex, uses stwol.sty; Plenary talk given at International Conference on High Energy Physics (ICHEP), Warsaw, July 1996High Energy Physics - Theorytext