ADD_KEY_MAP
     Adds one or more key maps to a key-map list.
  Syntax
     ADD_KEY_MAP (string1, {FIRST | LAST}, string2 [,...])
  Parameters
     string1              Specifies the name of the key-map list.
     FIRST                Specifies the key map is added to the beginning of
                          the key-map list.
     LAST                 Specifies the key map is added to the end of the
                          key-map list.
     string2              Specifies the name of the key map to be added to
                          the key-map list.  You can specify more than one
                          key map.  Key maps are added to the key-map list
                          in the order specified.  The order of a key map in
                          a key-map list determines precedence among any
                          conflicting key definitions.
  Example
     These statements create a key map named HELP_KEYS and add it to the
     default key-map list, TPU$KEY_MAP_LIST.  Key definitions in the new key
     map override those in the key maps already in the list.
     help_keys := CREATE_KEY_MAP ("help_keys");
     ADD_KEY_MAP ("TPU$KEY_MAP_LIST", "first", help_keys);
  Related Topics
     ADD_KEY_MAP          CREATE_KEY_MAP             CREATE_KEY_MAP_LIST
     DEFINE_KEY           GET_INFO                   REMOVE_KEY_MAP
     SET(KEY_MAP_LIST)    SET(PRE_KEY_PROCEDURE)     SET(POST_KEY_PROCEDURE)
     SET(UNDEFINED_KEY)   SHOW                       Key Maps and Key Map
     Lists