SICP

I'm now readin SICP.Its not a bad book at all.
Its notation however sucks:
(+ (* 3 (+ (* 2 4) (+ 3 5))) (+ (- 10 7) 6))
There is no way i could see which empty)( places contain which operators without reading entire string piece by piece.
This wouldn't work with larger strings.

>>6
FURTHER OPTIMIZATION:
function abs(x){return (x > 0) ? x : -x}