Describe the behavior of the following procedure:
(define (a-plus-abs-b a b)
((if (> b 0) + -) a b))
Note that the if procedure will itself return a procedure: either + or -. So, if b is greater than 0, the procedure evaluated will be:
(+ a b)
resulting in a positive number, whereas if b is less than 0 (i.e. negative), the procedure evaluated will be:
(- a b)
also resulting in a positive number.