2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/108900We explore the relations among quadratic modules, 2-crossed modules, crossed squares and simplicial groups with Moore complex of length 2.Journal of Homotopy and Related Structures (to appear)Category TheoryAlgebraic Topology18D35;18G30;18G50;18G55text