i was thinking that, too, while reading this. It has been a while since I wrote any Clojure, but I didn't remember ever using `ref-set` with STM. also, local

i was thinking that, too, while reading this. It has been a while since I wrote any Clojure, but I didn't remember ever using `ref-set` with STM. also, local bindings with `let` were the defacto standard.