OpenBSD-4.6/usr.bin/learn/lib/eqn/L3.2c

#once #create message
.ND
.PP
Modify "Example" to produce this output, then type "ready".
#once #create Ref
.LP
.EQ
x sup 2 + y sup 2 = z sup 2
.EN
.pl 1
#once #create Example
.LP
.EQ
xxx
.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
3.1d 10