anchor.diff:          type(spawn_t), intent(inout) :: spawn
           integer, intent(inout), optional :: determ_flags(:)
           integer, intent(in), optional :: lower_bound
  +        logical, intent(in), optional :: using_chebyshev
   
           integer :: i, istart, iend, j, k, pos, spawn_start, disp
           real(p) :: real_population(psip_list%nspaces)
  
positive.code: 
      end subroutine round_low_population_spawns
  
      subroutine insert_new_walkers(sys, psip_list, ref, annihilation_flags, spawn, determ_flags, lower_bound)
  
          ! Insert new walkers into the main walker list from the spawned list.
          ! This is done after all particles have been annihilated, so the spawned
  
negative.code:                 associate(spawned_population => spawn%sdata(spawn%bit_str_len+1:spawn%bit_str_len+spawn%ntypes, i), &
                          tbl=>sys%basis%tensor_label_len)
                      call insert_new_walker(sys, psip_list, annihilation_flags, k, int(spawn%sdata(:tbl,i), i0), &
                                             cheby_sign*int(spawned_population, int_p), ref)
                      ! Extract the real sign from the encoded sign.
                      real_population = cheby_sign*real(spawned_population,p)/psip_list%pop_real_factor
                      psip_list%nparticles = psip_list%nparticles + abs(real_population)
                  end associate
  
  