2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/69922We show that the category of presheaves of simplicial groupoids on a site $\mathcal{C}$ is a right proper simplicial model category. We define $G$-torsor of presheaf of 2-groupoids $G$, presheaf of simplicial groups $G$ and presheaf of simplicial groupoids $G$ on a site $\mathcal{C}$ and classify $G$-torsors by the homotopy classes $[\ast, \bar{W}G]$.34 pagesAlgebraic TopologyCategory Theory55U35; 55P15text