Return Stack >R n -- R:n Pops PS and push to RS 2>R x y -- R:x y Equivalent to SWAP >R >R R> R:n -- n Pops RS and push to PS 2R> R:x y -- x y Equivalent to R> R> SWAP I -- n Copy RS TOS to PS I' -- n Copy RS second item to PS J -- n Copy RS third item to PS