(datatype day

_____________
"Monday" : day;
_____________
"Tuesday" : day;
________________
"Wednesday" : day;
_______________
"Thursday" : day;
____________
"Friday" : day;
______________
"Saturday" : day;
_____________
"Sunday" : day;)

(datatype day

if (element? Day ["Monday" "Tuesday" "Wednesday" 
                  "Thursday" "Friday" "Saturday" "Sunday"])
 _______________________________________________
 Day : day;)

(datatype month

if (element? Month ["January" "February" "March"  "April"
                    "May" "June" "July" "August" "September"
                    "October" "November" "December"])
 _______________________________________________
 Month : month;)

(define decode-month
    {number --> month}
     1 -> "January"
     2 -> "February" 
     3 -> "March"  
     4 ->  "April"
     5 ->  "May" 
     6 ->  "June" 
     7 ->  "July" 
     8 ->  "August"
     9 ->  "September"
    10 ->  "October" 
    11 ->  "November"
    12 ->  "December")

(datatype employee

	if (element? E (read-file "employees.txt"))
  ___________________________________________
	E : employee;)

(datatype age

 if (number? Age)
 if (>= Age 18)
 if (<= Age 64)
 ____________
 Age : age;)