Coarse-Grid Correction for Nonelliptic and 
                        Singular Perturbation Problems

                                 Irad Yavneh 
                       Department of Computer Science 
                  Technion---Israel Institute of Technology
                             Haifa 32000, Israel
                                 October 1996


The suitability of coarse-grid correction operators for multigrid solution of
discretized nonelliptic partial differential equations is studied.  It is
found that the requirements for the orders of intergrid transfers and the
order of approximation of the coarse-grid operators differ in an important way
from the well-known ``rules'' pertaining to elliptic operators.  Both Galerkin
coarsening and coarsening schemes based on the differential operator are
examined, and new coarse-grid correction strategies are suggested in light of
this analysis.