2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/145620We relate the graph isomorphism problem to the solvability of certain systems of linear equations with nonnegative variables. This version replaces the two previous versions of this paper.12 pagesComputational ComplexityDiscrete MathematicsG.2.2; F.2.2text