code: def _recon_lcs(x, y):
      """
      Returns the Longest Subsequence between x and y.
      Source: http://www.algorithmist.com/index.php/Longest_Common_Subsequence
  
      :param x: sequence of words
      :param y: sequence of words
      :returns sequence: LCS of x and y
      """
      table = _lcs(x, y)
  
      def _recon(i, j):
          if i == 0 or j == 0:
              return []
          elif x[i - 1] == y[j - 1]:
              return _recon(i - 1, j - 1) + [(x[i - 1], i)]
          elif table[i - 1, j] > table[i, j - 1]:
              return _recon(i - 1, j)
          else:
              return _recon(i, j - 1)
  
      i, j = _get_index_of_lcs(x, y)
      recon_tuple = tuple(map(lambda r: r[0], _recon(i, j)))
      return recon_tuple
  
file_path: sumy/sumy/evaluation/rouge.py
imports: from __future__ import absolute_import
  from __future__ import division, print_function, unicode_literals
  from ..models.dom import Sentence
label_desc: Use image node_id 7 for calling a global function with example usage: _recon_lcs(x, y) and returns: recon_tuple, list, unknown, _recon, _recon