usr/lib/learn/editor/L39.1a

#print
Using the "^" character, you can easily put things
at the beginnings of lines.  For example
  s/^/***/
puts "***" at the beginning of the line.  Now edit
the file "text" and put the symbol '=' at the beginning
of lines 3 through 5. Then rewrite the file and type "ready".
#create Ref
beef
pork
=chicken
=duck
=turkey
lamb
fish
#create text
beef
pork
chicken
duck
turkey
lamb
fish
#user
#cmp text Ref
#log
#next
40.1a 10