>r
w -- core "to-r"
r>
-- w core "r-from"
r@
-- w ; R: w -- w core "r-fetch"
rdrop
-- gforth "rdrop"
2>r
w1 w2 -- core-ext "two-to-r"
2r>
-- w1 w2 core-ext "two-r-from"
2r@
-- w1 w2 core-ext "two-r-fetch"
2rdrop
-- gforth "two-r-drop"