K-THEORETICALLY SIMPLE VON-NEUMANN REGULAR-RINGS

The differences between simplicity of a von Neumann regular ring and s implicity of its ordered Grothendieck group K0 are investigated. In pa rticular, we construct examples of stably finite regular rings which a re not simple but have simple K0. All the nontrivial factor rings of t hese examples are directly infinite. Also, we prove that a simple regu lar ring satisfies weak comparability if and only if its category of f initely generated projective modules is strictly unperforated. (C) 199 5 Academic Press, Inc.