2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/50472The BRST algebraic proofs of the the nonrenormalization theorems for the beta functions of N=2 and N=4 Super Yang-Mills theories are reviewed.3 pages, contribution to SUSY 2000 EncyclopediaHigh Energy Physics - Theorytext