[TUHS] Paragraphs formatted differently depending on previous ones

[Douglas McIlroy]

Branden,

> The relevant function fits on one screen, if your terminal window is at
> least 36 lines high.  :)  (Much of it is given over to comments.)

>   https://git.savannah.gnu.org/cgit/groff.git/tree/src/roff/troff/env.cpp?id=d96a9c58bbe296b065fa250e3ea1e1a410cdde81#n2185

Actually there's still another function, spread_space that contains
the inner R-L and L-R loops. The whole thing has become astonishingly
complicated compared to what I remember as a few (carefully crafted)
lines of code in the early roff. I admire your intrepid forays into
the groff woods, of which this part must be among the less murky.

Doug