# bump --- advance line number and corresponding index simultaneously subroutine bump (line, ix, way) integer line, way pointer ix include SE_COMMON if (way == FORWARD) { # increment line number ix = Nextline (ix) if (ix == Line0) line = 0 else line += 1 } else { # decrement line number if (ix == Line0) line = Lastln else line -= 1 ix = Prevline (ix) } return end