changing line length in nroff

[SECAD]

.PP is not a "native" or "primitive" nroff command, but rather one belonging
to any of a number of packages (most likely ms) of macros, or auxiliary,
higher level commands.

The use of any but a very small subset of the native nroff commands
with the ms macro commands is fraught with hazard for a variety of reasons.

You have stumbled upon one of the more benign and easy to diagnose problems
associated with mixing the 2 sets of commands:

	Upon startup, the ms package makes its own copy of many of the
	values which control the appearance of your output, and frequently
	(eg: every time there is a new page) refreshes the "working" copy
	of those values from that originally made copy.

	With respect to this particular problem, and several similar
	ones, the trick is to change BOTH copies of the values.

	".ll whatever" changes nroff's working copy of the line length,
	               and the change takes effect immediately

	".nr LL whatever" changes ms's reference copy of the line length,
	                  and the effect is observed when ms next refreshes
	                  the working copy

	Note that the default unit for .ll is "m" (width of character "m"),
	so that ".ll 8" yields the same thing as ".ll 8m", 8 characters,
	whereas ".ll 8i" yields 8 inches and ".ll 8u", 8 units. In nroff,
	1 unit is 1/240th of an inch, so ".ll 8u" yields 1/30th of an inch.
	On the other hand, the default unit for .nr is "u", so ".nr LL 8"
	yields the same thing as ".nr LL 8u", 1/30th of an inch.
	".nr LL 8m" yields 8 characters and ".nr LL 8i", 8 inches.

	Obtaining a relative change with .nr is done similarly to .ll usage:
	"nr LL +8m" increases the reference value by 8 characters.