SICP chapter1

SICP_chapter1.scm

;; 1.1.2
(define size 2)

(* 5 size)

(define pi 3.14159)
(define radius 10)

(* pi (* radius radius))

(define circumference (* 2 pi radius))

;; 1.1.4
(define (square x)
  "documentation for square."
  (* x x))

(define (sum-of-square x y)
  "documentation for sum-of-square."
  (+ (square x) (square y)))

;; 1.1.6
(define (abs x)
   "documentation for abs."
   (cond ((> x 0) x)
         ((= x 0) 0)
         ((< x 0) (- x))))

(define (abs2 x)
  "documentation for abs2."
  (cond ((< x 0) (- x))
        (else x)))

(define (abs3 x)
  "documentation for abs3."
  (if (< x 0)
      (- x)
      x))

(define (more-than-5-and-less-than-10 x)
  "documentation for more-than-5-and-less-than-10."
  (and (> x 5) (< x 10)))
(define (is-big-or-equal-other x y)
  "documentation for is-big-or-equal-other."
  (or (> x y) (= x y)))

(define (is-big-or-equal-other2 x y)
  "documentation for is-big-or-equal-other2."
  (not (< x y)))