anchor.diff:  		  (setf (cdr accel-tail) (cddr accel-tail))
   		  (setf (cdr items-tail) (cddr items-tail))))
   	    (when errorp
  -	      (error 'command-not-present))))))
  +	      (error 'command-not-present :command-table-name
  +                     (command-table-designator-as-name table)))))))
     nil)
   
   (defun map-over-command-table-keystrokes (function command-table)
  
positive.code:                         (multiple-value-list (realize-gesture-spec :keyboard gesture))))
             (in-table (position gesture keystroke-accelerators :test #'equal)))
        (when (and in-table errorp)
          (error 'command-already-present))
        (if in-table
  	  (setf (nth in-table keystroke-items) item)
  	  (progn
  
negative.code: (defparameter *command-tables* (make-hash-table :test #'eq))
  
  (define-condition command-table-error (simple-error)
    ((command-table-name :reader error-command-table-name
                         :initform nil
                         :initarg :command-table-name))
    (:default-initargs :format-control "" :format-arguments nil))
  
  (defmethod print-object ((object command-table-error) stream)
    (print-unreadable-object (object stream :type t :identity t)
      (when (error-command-table-name object)
        (princ (error-command-table-name object) stream))))
  
  (defun command-table-designator-as-name (designator)
    "Return the name of `designator' if it is a command table,
  `designator' otherwise."
    (if (typep designator 'standard-command-table)
        (command-table-name designator)
        designator))
  
  (define-condition command-table-not-found (command-table-error)
    ())
  