gistfile1.txt

(define (calendars-overlap? cal1 cal2) 
    (ormap
        (lambda (app) 
            (calendars-overlap-step app (cal-part cal2 APPOINTMENTS))
        )
        (cal-part cal1 APPOINTMENTS)
    )
)

(define (calendars-overlap-step app apps)
    (if [empty? apps]
        #f
        (or 
            (appointments-overlap? app (car apps))
            (calendars-overlap-step app (cdr apps))
        )
    )
)