**************************************************************
Results for Exercise 5.6

Assertion OK:
(= (sum-func 5 10 (lambda (n) (* n n))) 355)

Assertion OK:
(= (sum-func 10 100 sqrt) 652.156946577112)


**************************************************************
Results for Exercise 5.7

Assertion OK:
(= (square 4) 16)

Assertion OK:
(= (cube 4) 64)


**************************************************************
Results for Exercise 5.8

Assertion OK:
(= (factorial 5) 120)

Assertion OK:
(= (sum-of-first 5) 15)


**************************************************************
Results for Exercise 5.11

Assertion OK:
(equal? (check-isbn 262010771) #t)

Assertion OK:
(equal? (check-isbn 262010770) #f)


**************************************************************
Results for Exercise 5.12

Assertion OK:
(equal? (check-upc 38000145001) #t)

Assertion OK:
(equal? (check-upc 38000154001) #f)

Assertion OK:
(equal? (check-upc 44300107250) #t)

Assertion OK:
(equal? (check-upc 44300107350) #f)