Here's a #rstats package that helps your variables remember how they got there. Just a quick experiment/proof of concept.
https://github.com/moodymudskipper/elephant
(as always @_ColinFay 's https://connect.thinkr.fr/hexmake/  is great to build a quick logo!)

I would have prefered to avoid `:=` and use `(<-` to do `(z) <- x + y`, but rhs is evaluated before we can "see" it with assignment functions.
Using {doubt} with {elephant} we can define a dubious syntax and do `? z <- x + y` however.
https://github.com/moodymudskipper/doubt