The R-lang manual has this example which no longer holds (I couldn't
think of a simple alternative):
As it happens, @R{}'s parser is not perfectly invertible, nor is its
deparser, as the following examples show
@example
> deparse(quote(c(1, 2)))
[1] "c(1, 2)"
> deparse(1:2)
[1] "c(1, 2)"
-Deepayan