You are correct. I failed to consider the implications of the different mechanics in the repl. I&#x27;m inclined to think the clojure repl is more conducive to experimenting. That is, you can change any part of your program to see what happens.  I guess one programmer&#x27;s sandbox is another programmer&#x27;s hellish nightmare of mutability.  For what it&#x27;s worth, I would never redefine a var actual code, but I can&#x27;t say it hasn&#x27;t been done by others.