That's not really relevant. According to the guy's own definition, Scheme is as immutable as Clojure, which is what he was specifically asking. They both have

That's not really relevant. According to the guy's own definition, Scheme is as immutable as Clojure, which is what he was specifically asking. They both have something like set!. If you want to wank off about Scheme not being 100% immutable, go right ahead, but it's clearly not what was being discussed.