mohanrajendran

(define (p) (p))

(define (test x y)
  (if (= x 0)
      0
      y))

(test 0 (p))

mohanrajendran

(define (a-plus-abs-b a b)
  ((if (> b 0) + -) a b))

When the if function is evaluated, based on the condition, the operator + or - is applied on the operands a and b. If b > 0, + operator is used, evaluating to a+b. Otherwise, - operator is issued which yields a-b. Ultimately, we evaluate a+|b|.

mohanrajendran

(define (sq x) (* x x))
; sq

(define (sumsq x y) (+ (sq x) (sq y)))
; sumsq

(define (largest2sq a b c)
        (cond ((and (<= a b) (<= a c)) (sumsq b c))
              ((and (<= b a) (<= b c)) (sumsq a c))
              (else (sumsq a b))))

mohanrajendran

(/ (+ 5 4 (- 2 (- 3 (+ 6 (/ 4 5))))) 
   (* 3 (- 6 2) (- 2 7)))
; -37/150

mohanrajendran

10
; 10

(+ 5 3 4)
; 12

(- 9 1)
; 8

(/ 6 2)