6.2.2150
ROLL
 
CORE EXT
 
( xu xu-1 ... x0 u -- xu-1 ... x0 xu )

Remove u. Rotate u+1 items on the top of the stack. An ambiguous condition exists if there are less than u+2 items on the stack before ROLL is executed.

See:
A.6.2.2150 ROLL.

Rationale:
2 ROLL is equivalent to ROT, 1 ROLL is equivalent to SWAP and 0 ROLL is a null operation.