107     if (strcmp(arg[7],"INF") == 0) zhi = BIG;  in RegBlock()
108     else if (domain->triclinic == 0) zhi = domain->boxhi[2];  in RegBlock()
109     else zhi = domain->boxhi_bound[2];  in RegBlock()
110   } else zhi = zscale*force->numeric(FLERR,arg[7]);  in RegBlock()
114   if (xlo > xhi || ylo > yhi || zlo > zhi)  in RegBlock()
126     extent_zhi = zhi;  in RegBlock()
149   if (x >= xlo && x <= xhi && y >= ylo && y <= yhi && z >= zlo && z <= zhi)  in inside()
168       x[2] < zlo || x[2] > zhi) return 0;  in surface_interior()
211   delta = zhi - x[2];  in surface_interior()
237       x[2] <= zlo-cutoff || x[2] >= zhi+cutoff) return 0;  in surface_exterior()
239       x[2] > zlo && x[2] < zhi) return 0;  in surface_exterior()
253   else if (x[2] > zhi) zp = zhi;  in surface_exterior()