anchor.diff:          call write_column_title(iunit, '# states', int_val=.true., justify=1)
           call write_column_title(iunit, '# spawn_events', int_val=.true., justify=1)
           if (present(nattempts)) then
  -            if (nattempts) call write_column_title(iunit, '# attempts', int_val=.true., justify=1)
  +            if (nattempts) call write_column_title(iunit, '# attempts', int_64_val=.true., justify=1)
           end if
           call write_column_title(iunit, 'R_spawn', low_prec_val=.true.)
           call write_column_title(iunit, '  time', low_prec_val=.true., justify=2)
  
positive.code: 
      end subroutine write_dmqmc_report_header
  
      subroutine write_column_title(io, key, int_val, low_prec_val, justify, sep)
  
          ! Write column headers using the same column width as write_qmc_var.
  
  
negative.code: 
          integer, intent(in) :: io
          character(*), intent(in) :: key
          logical, intent(in), optional :: int_val, int_64_val, low_prec_val
          integer, intent(in), optional :: justify
          character(1), intent(in), optional :: sep
          logical :: int_val_loc, int_64_val_loc, low_prec_val_loc
          character(20) :: key_str
          integer :: justify_loc, str_len
          character(1) :: sep_loc
  
          int_val_loc = .false.
          int_64_val_loc = .false.
          low_prec_val_loc = .false.
          justify_loc = 0
          sep_loc = ' '
          if (present(int_val)) int_val_loc = int_val
          if (present(int_64_val)) int_64_val_loc = int_64_val
          if (present(low_prec_val)) low_prec_val_loc = low_prec_val
          if (present(justify)) justify_loc = justify
          if (present(sep)) sep_loc = sep
  