2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/63745We calculate the ordered K_0-group of a graph C*-algebra and mention applications of this result to AF-algebras, states on the K_0-group of a graph algebra, and tracial states of graph algebras.6 pages, uses XY-pic. An error in Theorem 2.2 was corrected. At the referee's suggestion the paper was shortened and the title changedOperator Algebras46L55text