2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/79699Talk given at the conference "Visions in Mathematics toward the year 2000", August 1999, Tel-Aviv.25 pages; a few corrections made in the new versionQuantum Algebra17B66; 17B69; 81V22Classification of infinite-dimensional simple groups of supersymmetries and quantum field theorytext