; Returns a letter's place in the alphabet.
(define (a-z letter) (a-z-helper letter 1 '(a b c d e f g h i j k l m n o p q r s t u v w x y z) ) )
(define (a-z-helper letter number sent)
(if (equal? letter (first sent) )
number
(a-z-helper letter (+ number 1) (butfirst sent) ) ) )
; Returns the number of a month.
(define (month-number month) (month-number-helper month '(january february march april may june july august september october\
november december) 1) )
(define (month-number-helper month list counter)
(if (equal? month (first list) )
counter
(month-number-helper month (bf list) (+ counter 1) ) ) )