more minor cleanup; there is no reason to even pursue GMG here because there is no way to significantly exceed CFL and maintain accuracy using implicit time-stepping, regardless of solver performance
more minor cleanup; there is no reason to even pursue GMG here because there is no way to significantly exceed CFL and maintain accuracy using implicit time-stepping, regardless of solver performance

bueler/p4pdes,bueler/p4pdes,bueler/p4pdes,bueler/p4pdes