anchor.diff:      (assert-equal ___ how-many-in-list)
       (assert-equal ___ biggest-in-list))
     (let ((sum 0))
  -    "write your own do-list here to calculate the sum of some-primes"
  +    "write your own dolist here to calculate the sum of some-primes"
       "you may be interested in investigating the 'incf' function"
       ;(dolist ... )
       (assert-equal 999607602 sum)))
  
positive.code: 
  
  (defun vowelp (c)
    "returns true iff c is a vowel"
    (find c "AEIOUaeiou"))
  
  (defun vowels-to-xs (my-string)
  
negative.code:       variable in turn"
    (let ((how-many-in-list 0)
          (biggest-in-list (first some-primes)))
      "this dolist loops over some-primes, defined above"
      (dolist (one-prime some-primes)
        (if (> one-prime biggest-in-list)
            (setf biggest-in-list one-prime))
  