LET* vs LET
LET begins the scope of each local binding at the first form after all the local bindings have been established. (“Parallel”)
LET* begins the scope of each local binding immediately after its initial assignment. (“Sequential”)
> (let ((x 5) (y 10) (z 30) w)
> (let* ((x 5)(y (* x 2)) (z (* y 3)) w)