l12.1e

<B>Digital的Unix操作系统VAX 4.2源码</B>

#once #create message
.ND
.tr %$
.EQ
delim $$
.EN
.PP
There are also occasions when you want to omit
the left part and keep the right part.
This is a bit more complicated, since for obscure
reasons neqn won't let you actually leave the
left part out completely.
But you can ask it to print no character,
instead of using bars, by saying
   left ""  thing  right |
.LP
This is similar to the way we used quotes before, to get
a zero-width thing before a superscript.

For practice, modify file "Example" so it produces output
that looks like this, then type "ready".
.pl 1
#once #create Ref
.LP
.EQ
left ""
int from 0 to {2 pi} sin (x) dx ~=~
cos (x) right | sub 0 sup {2 pi}
.EN
.pl 1
#once #create Example
.LP
.EQ
replace me
.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