anchor.diff:        (setf (gethash "one" h2) "yat")
         (setf (gethash "two" h1) "yi")
         (setf (gethash "two" h2) "yi")
  -      (true-or-false? ___ (eq h1 h2))
  -      (true-or-false? ___ (equal h1 h2))
  -      (true-or-false? ___ (equalp h1 h2))))
  +      (true-or-false? nil (eq h1 h2)) ;; hmmm
  +      (true-or-false? nil (equal h1 h2))
  +      (true-or-false? t (equalp h1 h2))))
   
   
   (define-test test-changing-hash-tables
  
positive.code: 
    (setf (gethash 8 table-of-cube-roots) 2)
    (setf (gethash -3 table-of-cube-roots) -27)
    (assert-equal ___ (gethash -3 table-of-cube-roots))
    (assert-equal ___ (hash-table-count table-of-cube-roots))
  
    "accessing unset keys returns nil"
    (assert-equal ___ (gethash 125 table-of-cube-roots))))
  
  
  (define-test test-hash-key-equality
  
negative.code:       (setf value-and-exists (multiple-value-list (gethash "Obama" prev-pres)))
        (assert-equal value-and-exists '("Bush" t))
        (setf value-and-exists (multiple-value-list (gethash "Lincoln" prev-pres)))
        (assert-equal value-and-exists '("Buchanan" t))
        (setf value-and-exists (multiple-value-list (gethash "Washington" prev-pres)))
        (assert-equal value-and-exists '(nil t))
        (setf value-and-exists (multiple-value-list (gethash "Franklin" prev-pres)))
        (assert-equal value-and-exists '(nil nil))))
  
  
  (define-test test-make-your-own-hash-table
      "make a hash table that meets the following conditions"
    (let ((colors (make-hash-table :test #'equal))
          (values (make-hash-table)))
  
      (setf (gethash "blue" colors) (list 0 0 1))
      (setf (gethash "green" colors) (list 0 1 0))
      (setf (gethash "red" colors) (list 1 0 0))
      (setf (gethash "black" colors) 0)
  
      (assert-equal (hash-table-count colors) 4)
      (setf values (list (gethash "blue" colors)
                         (gethash "green" colors)
                         (gethash "red" colors)))
  
      (assert-equal values '((0 0 1) (0 1 0) (1 0 0)))))
  