2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/76605The concept of coreflexive set is introduced to study the structure of digraphs. New characterizations of line digraphs and nth-order line digraphs are given. Coreflexive sets also lead to another natural way of forming an intersection digraph from a given digraph.8 pages, 3 figuresCombinatorics05C20text