anchor.diff:    (string-copy str offset newstr 0 len)
     newstr)
   
  -(define (chomp str)
  -  (define len (string-length str))
  -  (if (and (> len 0) (eq? #\Newline (string-ref str (1- len))))
  -      (substring str 0 (1- len))
  -      str))
  -
   (define (string-equal? a b)
     (define len (string-length a))
     (and (= (string-length b) len)
  
positive.code: (define (last-cons l)
    (last-n-conses l 1))
  
  (define (list* l1 . l)
    (if (null? l) l1
      (begin
  
negative.code:                     (begin (set! pos (1+ pos))
                             (compare-chars)))))
           (compare-chars))))
  
  (define (string-flatten strs)
    (define pos 0)
    (dolist (str strs)
      (set! pos (+ pos (string-length str))))
    (define res (make-string pos))
    (set! pos 0)
    (dolist (str strs)
      (string-copy str 0 res pos (string-length str))
      (set! pos (+ pos (string-length str))))
    res)
  
  (define (string-concat . strs)
    (string-flatten strs))
  
  
  ;;; Vectors
  
  