Martinez-de-Albeniz, F. Javier; Nunez, Marina; Rafels, … - Facultat d'Economia i Empresa, Universitat de Barcelona - 2010
prove that the set of matrices leading to the same core form a join-semilattice with a nite number of minimal elements and a … unique maximum. We provide a characterization of the minimal elements. A sucient condition under which the join-semilattice …