4.3BSD-UWisc/lib/learn/eqn/L5.2d

#once #create message
.ND
.EQ
delim $$
.EN
.LP
Modify "Example" so it produces this output, then
type "ready".
.pl 1
#once #create Ref
.LP
.EQ
{partial e sup {-{x sup 2 + y sup 2} over 2}} over
{partial x} ~=~ f(x)
.EN
.pl 1
#once #create Example
.LP
.EQ
xxxx
.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
5.1e 10