Stop show with sound  Next slide in show -- Keyboard shortcut: 'n'  2 minutesLecture 5 - slide 21 : 26
Program 2
; R5RS syntactic abstraction:
(define-syntax my-delay 
  (syntax-rules ()
    ((delay expr)
     (lambda ()
        expr))))

; MzScheme syntactic abstraction:
(define-macro my-delay
  (lambda (expr)
    `(lambda () ,expr)))