%0 Journal Article %A Pardo Espino, Enrique %A Wehrung, F. %T Semilattices of groups and nonstable K-theory of extended Cuntz limits %D 2006 %U http://hdl.handle.net/10498/16086 %X We give an elementary characterization of those abelian monoidsM that are direct limits of countable sequences of finite direct sums of monoids of the form either (Z/nZ) ⊔ {0} or Z ⊔ {0}. This characterization involves the Riesz refinement property together with lattice-theoretical properties of the collection of all subgroups of M (viewed as a semigroup), and it makes it pos- sible to express M as a certain submonoid of a direct product ×G, where is a distributive semilattice with zero and G is an abelian group. When applied to the monoids V (A) appearing in the nonstable K-theory of C*-algebras, our results yield a full description of V (A) for C*-inductive limits A of finite sums of full matrix algebras over either Cuntz algebras On, where 2 ≤ n < ∞, or corners of O1 by projections, thus extending to the case including O1 earlier work by the authors together with K.R. Goodearl. %~ Universidad de Cádiz