':param fileids: A list specifying the fileids that should be used.
:return: the given file(s) as a list of paragraphs, each encoded as a
list of sentences, which are in turn encoded as a list of
tuples of the word and the corresponding lemma (word, lemma)
:rtype: list(List(List(tuple(str, str))))'

def lemma_paras(self, fileids=None):

    return concat([MTEFileReader(os.path.join(self._root, f)).lemma_paras() for f in self.__fileids(fileids)])
