anchor.diff:  (defun unequip-char (ch pos mode disable-checks)
     (assert (< 0 pos +num-wears+) nil "Illegal pos in unequip-char")
     (let ((obj nil))
  -    (case mode
  +    (ecase mode
         (:worn
          (assert (get-eq ch pos) nil
                  "eq NIL at pos ~d" pos)
  
positive.code:   "Extract an object from the world"
    (cond
      ((worn-by-of obj)
       (when (unequip-char (worn-by-of obj) (worn-on-of obj)
                           (if (eql obj (aref (equipment-of (worn-by-of obj))
                                              (worn-on-of obj)))
                               :worn
                               :implant)
                           nil)
         (error "Inconsistent worn-by and worn-on references!")))
      ((in-room-of obj)
       (obj-from-room obj))
      ((carried-by-of obj)
  
negative.code:   (assert (<= 0 pos +num-wears+) nil "Illegal pos in equip-char")
    (assert (not (carried-by-of obj)) nil "Object is carried-by when equipped")
    (assert (not (in-room-of obj)) nil "Object is in-room when equipped")
    (ecase mode
      (:worn
       (assert (not (get-eq ch pos)) nil "~a is already equipped: ~a"
               (name-of ch)
  