anchor.diff:  (define-key *global-keymap* "C-@" 'undefined-key)
   (define-key *global-keymap* "C-a" 'undefined-key)
   (define-key *global-keymap* "C-b" 'undefined-key)
  -(define-key *global-keymap* "C-c" 'undefined-key)
  +;(define-key *global-keymap* "C-c" 'undefined-key)
   (define-key *global-keymap* "C-d" 'undefined-key)
   (define-key *global-keymap* "C-e" 'undefined-key)
   (define-key *global-keymap* "C-f" 'undefined-key)
  
positive.code:      (kbd-keys (cons string-or-first-key keys)))))
  
  (defun keymap-find-keybind (keymap key)
    (let ((cmd (gethash key (keymap-table keymap))))
      (or cmd
          (let ((keymap (keymap-parent keymap)))
            (when keymap
              (keymap-find-keybind keymap key)))
          (keymap-undef-hook keymap))))
  
  (defun search-keybind-all (name)
    (let ((name (intern (string-upcase name) :lem))
  
negative.code:     (unless (and (kbd-p kbd)
                   (every #'characterp (kbd-list kbd)))
        (error "define-key: ~s is illegal key" key))
      (define-key-internal keymap kbd fun)))
  
  (defun define-key-internal (keymap kbd fun)
    (do ((rest (kbd-list kbd) (cdr rest)))
        ((null (cdr rest))
         (setf (gethash (car rest) (keymap-table keymap)) fun))
      (let ((k (car rest)))
        (let ((cmd (gethash k (keymap-table keymap))))
          (if (keymap-p cmd)
              (setf keymap cmd)
              (let ((new-keymap (make-keymap)))
                (setf (gethash k (keymap-table keymap))
                      new-keymap)
                (setf keymap new-keymap)))))))
  
  (defun kbd-to-string (key)
    (format nil "~{~A~^~}"
  