2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/218595It is shown that the category of presheaves of simplicial groupoids and the category of presheaves of 2-groupoids have Quillen closed model structures. Furthermore, their homotopy categories are equivalent to the homotopy categories of simplicial presheaves and homotopy 2-types, respectively.17 pagesAlgebraic TopologyCategory Theorytext