| Curtail | }: _ | 
| }:y drops the last item of y, 
and is equivalent to _1 }. y . Thus: | 
   ]y=: a. {~ (a. i. 'A') + i. 4 5
ABCDE
FGHIJ
KLMNO
PQRST
   f=: }: ; {:
   f y
+-----+-----+
|ABCDE|PQRST|
|FGHIJ|     |
|KLMNO|     |
+-----+-----+
   g=: }: ,.@; {:
   g y
+-----+
|ABCDE|
|FGHIJ|
|KLMNO|
+-----+
|PQRST|
+-----+
   h=: {. ,.@; }.
   h y
+-----+
|ABCDE|
+-----+
|FGHIJ|
|KLMNO|
|PQRST|
+-----+
   }:"1 y
ABCD
FGHI
KLMN
PQRS