I had a vague memory that pr could be made
to number lines, but a quick check of the 7/e
manual says no.
I expect Dan's right, and none of the 127 folks
felt much need to number lines on printouts
so nobody wrote the obvious simple tool.
Ironic, since the Unix PDP-11 used by the patent
licensing office (and I think shared with the
research group, and that was how their first
PDP-11 was justified and funded) happened
because the patent folks needed line-numbered
output and roff was easily modified to do that.
Maybe Doug or Ken or Steve has first-hand
memories.
Norman Wilson
Toronto ON
(on a train shuffling toward Buffalo)