Hello, I am having a problem understanding how these functions update the underlying ref, atom etc. The docs say: (apply f current-value-of-identity args) (def one (atom 0)) (swap! one inc) ;; => 1 So I am wondering how it got "expanded" to the apply form. It's not mentioned what exactly 'args' in the apply form is. Is it a sequence of arguments or are these separate values? Was it "expanded" to: (apply inc 0) ; obviously this wouldnt work, so that leaves only one possibility (apply inc 0 '()) (swap! one + 1 2 3) ;; #=> 7 Was it: (apply + 1 1 2 3 '()) ;or (apply + 1 [1 2 3]) (def two (atom [])) (swap! two conj 10 20) ;; #=> [10 20] Was it: (apply conj [] [10 20]) ;or (apply conj [] 10 20 '()) If I swap with a custom function like this: (def three (atom 0)) (swap! three (fn [current elem] (println (class elem))) 10) ;;#=> java.Lang.Integer Which means that the value '10' doesnt magically get changed into a seq '(10) and leads me to the conclusion, that it gets "expanded" to: (apply f current-value-of-identity arg1 arg2 arg3... '()) Is that a correct assumption and the docs are simply lacking a better description?