(self)
return res
r"""Return the lower central series for the group.

        The lower central series for a group ``G`` is the series
        ``G = G_0 > G_1 > G_2 > \ldots`` where
        ``G_k = [G, G_{k-1}]``, i.e. every term after the first is equal to the
        commutator of ``G`` and the previous term in ``G1`` ([1], p.29).

        Returns
        =======

        A list of permutation groups in the order
        ``G = G_0, G_1, G_2, \ldots``

        Examples
        ========

        >>> from sympy.combinatorics.named_groups import (AlternatingGroup,
        ... DihedralGroup)
        >>> A = AlternatingGroup(4)
        >>> len(A.lower_central_series())
        2
        >>> A.lower_central_series()[1].is_subgroup(DihedralGroup(2))
        True

        See Also
        ========

        commutator, derived_series
r"""Return the lower central series for the group.
r Return the lower central series for the group .
def lower_central_series(self):
        r"""Return the lower central series for the group.

        The lower central series for a group ``G`` is the series
        ``G = G_0 > G_1 > G_2 > \ldots`` where
        ``G_k = [G, G_{k-1}]``, i.e. every term after the first is equal to the
        commutator of ``G`` and the previous term in ``G1`` ([1], p.29).

        Returns
        =======

        A list of permutation groups in the order
        ``G = G_0, G_1, G_2, \ldots``

        Examples
        ========

        >>> from sympy.combinatorics.named_groups import (AlternatingGroup,
        ... DihedralGroup)
        >>> A = AlternatingGroup(4)
        >>> len(A.lower_central_series())
        2
        >>> A.lower_central_series()[1].is_subgroup(DihedralGroup(2))
        True

        See Also
        ========

        commutator, derived_series

        """
        res = [self]
        current = self
        next = self.commutator(self, current)
        while not current.is_subgroup(next):
            res.append(next)
            current = next
            next = self.commutator(self, current)
        return res
def lower_central_series ( self ) : res = [ self ] current = self next = self . commutator ( self , current ) while not current . is_subgroup ( next ) : res . append ( next ) current = next next = self . commutator ( self , current ) return res