Re: [Groff] Horizontal rule w/ length a fraction of the page width?

[Tadziu Hoffmann]

> >   \l'\n(.l/1.25'
> 
> This doesn't work correctly.

In Solaris troff it does, because that troff uses only 10 units
per point (100 units per em for a 10-point font), so it doesn't
encounter an arithmetic overflow when evaluating [line length
in units]*[units per em] as groff does with 1000 units per point.
If you reduce the line length to about 2 inches (with the
default point size of 10) or reduce the point size to 4 (with
the default line length), then it works in groff as well.

> >   \l'\n(.l*.80'
> 
> This doesn't work correctly too.

(Because you're not canceling scale factors as you would in
a division.)