Re: "mom": How to transition from two columns back to one?

[Steve Ross]

Hi Peter,

> Steve --
>
> On Tue, Dec 17, 2019, Steve Ross via wrote:
> > Is there a way in "mom" to force it to (more or less) evenly fill
> > both columns with text and then exit back to a single column mode?
>
> Yes and no. :)
>
> It's a little hard to grasp precisely what you want from your ASCII
> representation, but assuming a page that has 2-column text at the
> top with some single-column, full-measure text underneath, you first
> have to balance the columns yourself using .COL_NEXT or .COL_BREAK.

Thanks, my ASCII-diagram was mangled somehow, but your assumptions
are correct.
>
> At the spot you want to break out of column mode, enter
>
> .SP
> .rr #COLUMNS
> .L_MARGIN \n[#DOC_L_MARGIN]u
> .LL \\n[#DOC_L_LENGTH]u
>
Thanks. This works as advertised. I appreciate your help.
 
As a follow-up question, and after the above commands, why does
     \n[#DOC_L_LENGTH]
return the value of DOC_L_LENGTH (e.g., 468000) in machine units while,
for example, both
     \n[#LL]
and
     \n[LL]
return the value of zero? 
And likewise for, for example,
     \n[#QUOTE_INDENT]
and
     \n[QUOTE_INDENT]
I think that I don't understand how to access the LL and 
QUOTE_INDENT registers.

> Subsequent text will be over the full measure.
>
> If you wish to return to 2-column mode *on the same page*, enter
>
> .SP
> .nr #COLUMNS 1
> .nr #COL_NUM 1
> .L_MARGIN \n[#DOC_L_MARGIN]u
> .LL \n[#COL_L_LENGTH]u
> .COL_MARK
Thanks again. This works as well.

-- Steve Ross