4.3BSD-UWisc/lib/learn/eqn/L2.1f

#once #create message
.ND
.LP
One of the most common problems in using neqn is forgetting
to leave spaces or tildes around "magic" words like "pi"
or "int" or "sum".  The result is that the magic words
cease to be magic, and just look like ordinary strings
of letters.

In the file "Example", there are several such errors.
Find them, and fix them so the output looks
like this, then type "ready".
.pl 1
#once #create Ref
.LP
.EQ
sum ~=~ pi ~+~1
.EN
.EQ
a~=~ pi (x)
.EN
.EQ
alpha ~=~ beta ~+~ gamma ~+~ delta
.EN
.pl 1
#once #create Example
.LP
.EQ
sum=pi+1
.EN
.EQ
a=pi(x)
.EN
.EQ
alpha=beta+gamma+delta
.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
3.1a 10