anchor.diff:  				:key #'car
   				:start 3))))
   
  +(deftest trues (hof)
  +  (let alist '((a 1) (b 2) (c 3))
  +    (assert-equal '((c 3) (a 1))
  +                  (trues [assoc _ alist]
  +                         '(c d a)))))
  +
   ;;;; Tests for list.
   
   (deftest range (list)
  
positive.code:                            (whiler x (read :eof t) t
                               (a x))))))
  
  ;;;; Tests for memoize.
  
  ;; This serves as a test for memo and defmemo.
  
negative.code:   (assert-false (case 'c a 1 b 2 (t) 3))
    (assert-eql 3 (case t a 1 b 2 (t) 3 t 4)))
  
  (deftest caselet (conditionals)
    (assert-eql 5
      (caselet x 10
        10 5
        20 30
        t  x))
    (assert-eql 30
      (caselet x 20
        10 5
        20 30
        t x))
    (assert-eql 50
      (caselet x 50
        10 5
        20 30
        t x)))
  
  ;;;; Tests for print.
  
  (deftest pr (print)
    (assert-equal "hello world 5"
  