anchor.diff:    (replace dest src :start1 dest-index :end1 (+ dest-index len)
              :start2 src-index))
   
  -;;; Vectors
  +;;; Vector primitives
   
   (defun make-vector (len)
     (make-array len))
  
positive.code: (declaim (optimize (debug 2)))
  
  ;;; Language
  
  (define-symbol-macro true t)
  (define-symbol-macro false nil)
  
negative.code: 
  (defun string-symbolcase (str) (string-upcase str))
  
  ;;; String primitives
  
  (defun string-length (str)
    (length str))
  