xscheme-yank-pop
xscheme-yank-pop is an interactive compiled Lisp function in `xscheme.el
'.
(xscheme-yank-pop ARG)
Insert or replace a just-yanked expression with an older expression.
If the previous command was not a yank, it yanks.
Otherwise, the region contains a stretch of reinserted
expression. yank-pop deletes that text and inserts in its
place a different expression.
With no argument, the next older expression is inserted.
With argument n, the n'th older expression is inserted.
If n is negative, this is a more recent expression.
The sequence of expressions wraps around, so that after the oldest one
comes the newest one.