(+ (+ a 2) (+ b 2))
(+ 4 a b)

(+ 1 2 b)
(+ 3 b)

(+ 1 2 3)
6

(* (/ 2 3) (/ 3 2))
1

# TODO
(* (/ -2 3) (/ 3 2))
-1


(* (* a b 1) (* c d))
(* a b c d)

(+ (+ a b) (+ c d))
(+ a b c d)

(+ (+ a b 1) (+ c d 3))
(+ 4 a b c d)

(^ 4 -1)
(/ 1 4)

(^ (/ 2 3) -1)
(/ 3 2)

(^ (/ 1 3) -1)
3