def atoms(self):
        """
        Returns all the elements of a permutation

        Examples
        ========

        >>> Permutation([0, 1, 2, 3, 4, 5]).atoms()
        {0, 1, 2, 3, 4, 5}
        >>> Permutation([[0, 1], [2, 3], [4, 5]]).atoms()
        {0, 1, 2, 3, 4, 5}

        """
        return set(self.array_form)