fprintf(qhferr,"qhull input error: 'Qg QVn' (only good vertex) does not work with merging.\nUse 'QJ' to joggle the input or 'Q0' to turn off merging.\n");
qh_errexit(qh_ERRinput,NULL,NULL);
}
if(!(qhGOODthreshold||qhGOODpoint
||(!qhMERGEexact&&!qhPREmerge&&qhGOODvertexp))){
fprintf(qhferr,"qhull input error: 'Qg' (ONLYgood) needs a good threshold ('Pd0D0'), a\n\
good point (QGn or QG-n), or a good vertex with 'QJ' or 'Q0' (QVn).\n");