2.11BSD/src/share/learn/editor/L57.1a

#print
For symmetry, you can use

+

instead of either ".+1p" or an empty line (just a newline).
The only advantage that + has is that you can repeat it:

++

prints the second following line, and 

+++

the third.  The same is true of -.  If the current line is
line number 10, what line number is -- going to be?
(Hint:  you can find out by editing a file such as "pres",
saying "10p", and then saying "--",
and then saying ".=" - remember the "=" command?)
When you find out, type "answer N" where
N is the number.
#create pres
George Washington
John Adams
Thomas Jefferson
James Madison
James Monroe
John Quincy Adams
Andrew Jackson
Martin van Buren
William Henry Harrison
John Tyler
James K. Polk
Franklin Pierce
Millard Fillmore
James Buchanan
Abraham Lincoln
#copyin
#user
#uncopyin
#match 8
#log
#next
60.1a 10
60.2a 5