2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/70037We give a computational algorithm which decides if a braid is quasipositive or not. A braid is quasipositive if it's a product of conjuguates of generators. For this, we use the theory of Garside and the combinatorials properties of the Artin monoid.20 pages.Revised version of march 2004Geometric TopologyCombinatorics05E15text