Preconditioning Cell-centered finite difference equations 
              on grids with local refinement}

                      Ilya. D. Mishev
Abstract

We consider cell-centered finite difference discretizations with 
local refinement for nonsymmetric boundary value problems. 
Preconditioners with mesh independent convergence properties for 
corresponding matrices are constructed.
%nonsymmetric boundary value discretized by finite difference schemes 
%on cell-centered grid with local refinement are constructed. 
The method is illustrated with numerical experiments.