OpenBSD-4.6/usr.bin/learn/lib/eqn/L10.1c

#print
There are several warnings in order about mark and lineup.
First, remember that you must use ".EQ I" or ".EQ L".
Second, there can only be one mark or one lineup in any given
equation.
Finally, what you are doing must make sense, or
your results may be not what you wanted.

Does this sequence produce output with the equals signs
lined up?
  .EQ L
  x mark = y
  .EN
  .EQ L
  x+y mark = z
  .EN
Answer yes or no.
#copyin
#user
#uncopyin
#match no
#log
#next
11.1a 10
10.2c 5