(cond
    [(< 1 3) "looky"]
    [(< 1 4) "won't get here"]
    [else    "NOT here either"]
)

(define HEIGHT 5.5)

(cond 
    [(> HEIGHT 6.0)
        "She is over 6 ft tall"]
    [else
        "She is NOT over 6 ft"]
)

; remember absolute value?
;
; abs-value(x) = x if x >= 0
;                -x if x < 0

; abs-value : number -> number
; purpose: expects a number, and returns its 
;    absolute value, where:
;    abs-value(x) = x if x >= 0
;                  -x if x < 0

(EXAMPLE (abs-value -5) 5)
(EXAMPLE (abs-value 7) 7)
(EXAMPLE (abs-value 0) 0)

(define  (abs-value a-number)
    (cond 
        [(< a-number 0)  (* -1 a-number)]
        [else            a-number]
    )
)

(abs-value -5)
(abs-value 7)

; hey, assume time is given as the hour of the
;    day written in 24-hour format

; greeting: string number -> string
; purpose: expects a name and an hour of the
;    day given in 24-hour format,
;    and returns a personalized greeting
;    appropriate for the time of day
;
;    morning ends at: noon [0, 12)
;    afternoon ends at: 17 [12, 17)
;    evening ends at: 23   [17, 23]
;    for an out-of-bounds time, we'll complain

(EXAMPLE (greeting "Charlie"-3) 
         "NOT A TIME, Charlie!")
(EXAMPLE (greeting "Dennis" 0)
         "Good morning, Dennis!")
(EXAMPLE (greeting "Susan" 1)
         "Good morning, Susan!")
(EXAMPLE (greeting "Dennis" 12)
         "Good afternoon, Dennis!")
(EXAMPLE (greeting "Charlie" 15)
         "Good afternoon, Charlie!")
(EXAMPLE (greeting "Susan" 17)
         "Good evening, Susan!")
(EXAMPLE (greeting "Charlie" 19)
         "Good evening, Charlie!")
(EXAMPLE (greeting "Dennis" 23)
         "Good evening, Dennis!")
(EXAMPLE (greeting "Susan" 44)
         "NOT A TIME, Susan!")

(define (greeting name the-hour)
    (cond
        [(and (>= the-hour 0) 
              (< the-hour 12)) (string-append "Good morning, "
                                              name
                                              "!")]
        [(and (>= the-hour 12) 
              (< the-hour 17)) (string-append "Good afternoon, "
                                              name
                                              "!")]
        [(and (>= the-hour 17) 
              (<= the-hour 23)) (string-append "Good evening, "
                                               name
                                               "!")]
        [else (string-append "NOT A TIME, "
                             name
                             "!")]
    )              
)

(greeting "Susan" 267)
(greeting "Charlie" 15)