anchor.diff:  (in-package :lem)
   
  -(export '(last-read-key-sequence
  +(export '(*input-hook*
  +          last-read-key-sequence
             start-record-key
             stop-record-key
             key-recording-p
  
positive.code:   (let ((key (if (null *unread-keys*)
                   (read-key-1)
                   (pop *unread-keys*))))
      (when *key-recording-p*
        (push key *record-keys*))
      key))
  
  (defun unread-key (key)
  
negative.code:           execute-key-sequence
            sit-for))
  
  (defvar *input-hook* '())
  
  (defvar *key-recording-p* nil)
  (defvar *record-keys* nil)
  (defvar *unread-keys* nil)
  
  (let (last-read-key-sequence)
  