@Section
   @Title { The empty object }
   @Tag { empty }
@Begin
@PP
It is possible to produce examples in which an object is clearly
empty. @Index { empty object }
missing:
@ID @Code "{ @I   }"
The @Code "@I" symbol is supposed to italicize the following object,
but in this example there isn't one.  A more plausible example is
@ID @OneRow @Code {
"@PP"
"@PP"
}
There are supposed to be paragraph objects between paragraph symbols,
but here there aren't.
@PP
Wherever an object is clearly missing, Lout inserts an @I { empty object },
which is a rectangle of size zero by zero that prints as nothing.  Here
are two other ways to get an empty object:
@ID @Code "{}     \"\""
Braces always enclose an object, so Lout is obliged to insert an empty
object between them; the two double quotes make a word with no characters
in it, which is taken to be an empty object.
@End @Section