code: def _pull_out_perm_lhs(lhs, rest, out_port, in_port):
      
      out_inv, lhs_red = lhs._factor_lhs(out_port)
      return lhs_red << Feedback.create(SeriesProduct.create(*rest),
                                        out_port=out_inv, in_port=in_port)
docs: Pull out a permutation from the Feedback of a SeriesProduct with itself.
  
      Args:
          lhs (CPermutation): The permutation circuit
          rest (tuple): The other SeriesProduct operands
          out_port (int): The feedback output port index
          in_port (int): The feedback input port index
  
      Returns:
          Circuit: The simplified circuit