anchor.diff:      "The mapcar function can be applied to
        more than one list. It applies a function
        to successive elements of the lists."
  -  (assert-equal ____ (mapcar #'* '(1 2 3) '(4 5 6)))
  -  (assert-equal ____ (mapcar #'list '("lisp" "are") '("koans" "fun"))))
  +  (assert-equal '(4 10 18) (mapcar #'* '(1 2 3) '(4 5 6)))
  +  (assert-equal '(("lisp" "koans") ("are" "fun")) (mapcar #'list '("lisp" "are") '("koans" "fun"))))
   
   
   (define-test test-transpose-using-mapcar
  
positive.code:     "mapcar and reduce are a powerful combination.
       insert the correct function names, instead of WRONG-FUNCTION-X
       to define an inner product."
    (defun inner (x y) 
      (reduce #'WRONG-FUNCTION-2 (mapcar #'WRONG-FUNCTION-3 x y)))
    (assert-equal 32 (inner '(1 2 3) '(4 5 6)))
    (assert-equal 310 (inner '(10 20 30) '(4 3 7))))
  
negative.code:   (defun WRONG-FUNCTION-1 (&rest rest) '())
    (defun transpose (L) (apply #'mapcar (cons #'WRONG-FUNCTION-1 L)))
    (assert-equal '((1 4 7)
                    (2 5 8)
                    (3 6 9))
                  (transpose '((1 2 3)
                               (4 5 6)
                               (7 8 9))))
    (assert-equal '(("these" "pretzels" "are")
                    ("making" "me" "thirsty"))
  