code: def append(self, value):
          
          if self._avm is not None and not self.terminated:
              path = self._last_path
              if path:
                  path += '.'
              self[path + LIST_HEAD] = value
              self._last_path = path + LIST_TAIL
              self[self._last_path] = AVM()
          else:
              raise TdlError('Cannot append to a closed list.')
docs: Append an item to the end of an open ConsList.
  
          Args:
              value (:class:`Conjunction`, :class:`Term`): item to add
          Raises:
              :class:`TdlError`: when appending to a closed list