;;  ------------------------------------------------------------------------
;; |   FILE           :  opening-exercise.rkt                               |
;; |   AUTHOR         :  Eugene Wallingford                                 |
;; |   CREATION DATE  :  2024/03/19                                         |
;; |   DESCRIPTION    :  demonstrating let expressions                      |
;;  ------------------------------------------------------------------------

#lang racket

;; --------------------------------------------------------------------------
;; exercise 1 

(define exercise1
  (lambda ()
    (let ((x 5)
          (y 6)
          (z 7))
      (- (+ x z) y))))

;; --------------------------------------------------------------------------
;; exercise 2

;; (define exercise2
;;   (lambda ()
;;     (let ((x 13)
;;           (y (+ 6 x))
;;           (z x))
;;       (- (+ x z) y))))

; --------------------------------------------------------------------------
; exercise 2b

(define exercise2b
  (lambda ()
    (let ((x 13))
      (let ((y (+ 6 x))
            (z x))
        (- (+ x z) y)))))

;; --------------------------------------------------------------------------
;; exercise 2c

;; (define exercise2c
;;   (lambda ()
;;     (let ((x 13))
;;       (let ((y (+ y x))
;;             (z x))
;;         (- (+ x z) y)))))

;; --------------------------------------------------------------------------