l11.1a

<B>Digital的Unix操作系统VAX 4.2源码</B>

#once #create message
.ND
.tr %$
.EQ
delim $$
.EN
.LP
We have introduced a fair number of "magic" words like
sub and sup and over and pi and sum.  What happens if
you need to print an equation that contains one of these
words __as ____text, like this:
.EQ
e sub "pi"
.EN

The way to turn off special meanings of magic words is
to enclose them in the double quotes "...".  The $e sub "pi"$
was printed with
  .EQ
  e sub "pi"
  .EN

Using this knowledge, modify file "Example" so it produces output
that looks like the following, then type "ready".
.pl 1
#once #create Ref
.LP
.EQ
lim "sup" f( "pi" ) = p cdot i
.EN
.pl 1
#once #create Example
.LP
.EQ
lim sup f( pi ) = p cdot i
.EN
.pl 1
#
#once neqn Ref | nroff >X1 &
#once neqn message Ref | nroff -T$term %s/tinyms -
#user
neqn Example | nroff >X2
#cmp X1 X2
#log
#next
11.1b 10