Interpretation semantics for this word are undefined.
( x1 x2
( R: -- x1 x2
Transfer cell pair x1 x2
to the return stack.
Semantically equivalent to SWAP >R >R
The primary advantage of 2>R is that it puts the top
stack entry on the top of the return stack. For instance, a
double-cell number may be transferred to the return stack and
still have the most significant cell accessible on the top of
the return stack.