> > > \l'\n(.l/1m'
> > \l'\n[.l]u' I think what should be considered here is that groff only does integer arithmetic. Therefore, in the first case the length of the line will get truncated to an integer number of ems, whereas in the second case the length of the line will match the width of filled text lines as closely as possible within the limits of the device resolution. Thus I suggest that the second way is generally preferable. On a high-resolution device it would be even better to use the graphical line-drawing function: \D'l \n(.lu 0'
