anchor.diff:    (assert-equal '(6 9) (group (range 1 5) :by 3 :with #'+))
     (assert-equal '(3 7 11) (group (range 1 6) :with #'+)))
   
  +(deftest last1 (list)
  +  (assert-eql 10 (last1 (range 1 10)))
  +  (assert-eql 'c (last1 '(a b c))))
  +
  +(deftest flat (list)
  +  (assert-equal (range 1 5) (flat '(((1) 2) (3 4) 5)))
  +  (assert-equal (range 1 5) (flat (range 1 5)))
  +  (assert-equal (range 1 5) (flat '(((1 2 3 4 5))))))
  +
  +(deftest len< (list)
  +  (assert-true  (len< '(1 2 3) 4))
  +  (assert-false (len< '(1 2 3) 3)
  +  (assert-false (len< '(1 2 3) 2))))
  +
  +(deftest len> (list)
  +  (assert-true  (len> '(1 2 3) 2))
  +  (assert-false (len> '(1 2 3) 3))
  +  (assert-false (len> '(1 2 3) 4)))
  +
   (deftest n-of (list)
     (assert-equal '(1 1 1) (n-of 3 1))
     (let x 0
  
positive.code:   (assert-eq 'hello (fromstring "Hello World" (read)))
    (assert-equal "Hello World" (fromstring "Hello World" (read-line)))
    (assert-eql 123 (fromstring "123" (parse-integer (read-line)))))
  
negative.code: (defsuite list (clamp))
  (defsuite conditionals (clamp))
  (defsuite print (clamp))
  (defsuite fns (clamp))
  (defsuite fnops (clamp))
  
  ;;;; Tests for base.
  
  