if Cursor_pane.col < 1 then return end
  clear_all_search_terms()
  local pane = Surface[Cursor_pane.col][Cursor_pane.row]
  if pane == nil then
    return
  end
  print('search previous', Cursor_pane.col, Cursor_pane.row, pane.cursor1.line, pane.cursor1.pos)
  local old_cursor_in_cursor_pane = {line=pane.cursor1.line, pos=pane.cursor1.pos}
  -- scan current pane up from cursor
  if search_previous_in_pane(Surface[Cursor_pane.col][Cursor_pane.row]) then
    print('found in same pane', pane.cursor1.line, pane.cursor1.pos)
    return
  end
  pane.cursor1 = old_cursor_in_cursor_pane
  -- scan current column down from current pane
  for current_pane_index=Cursor_pane.row-1,1,-1 do
    local pane = Surface[Cursor_pane.col][current_pane_index]
    pane.cursor1 = {line=#pane.lines, pos=#pane.lines[#pane.lines].data+1}
    if search_previous_in_pane(pane) then
      Cursor_pane.row = current_pane_index
      print('found in same column', Cursor_pane.col, Cursor_pane.row, pane.cursor1.line, pane.cursor1.pos)
      return
    end
  end
  local current_column_index = 1 + (Cursor_pane.col-2)%#Surface  -- (i-1)%#Surface in the presence of 1-indexing
  -- scan columns past current, looping around
  while true do
    print('column', current_column_index)
    for current_pane_index = #Surface[current_column_index],1,-1 do
      local pane = Surface[current_column_index][current_pane_index]
      pane.cursor1 = {line=#pane.lines, pos=#pane.lines[#pane.lines].data+1}
      if search_previous_in_pane(pane) then
        Cursor_pane = {col=current_column_index, row=current_pane_index}
        print('found', Cursor_pane.col, Cursor_pane.row, pane.cursor1.line, pane.cursor1.pos)
        return
      end
    end
    -- loop update
    current_column_index = 1 + (current_column_index-2)%#Surface  -- i = (i-1)%#Surface in the presence of 1-indexing
    -- termination check
    if current_column_index == Cursor_pane.col then
      break
    end
  end
  -- scan current column from bottom current pane
  for current_pane_index=#Surface[Cursor_pane.col],Cursor_pane.row+1,-1 do
    print('same column', current_pane_index)
    if search_previous_in_pane(Surface[Cursor_pane.col][current_pane_index]) then
      Cursor_pane.row = current_pane_index
      print('found in same column', Cursor_pane.col, Cursor_pane.row, pane.cursor1.line, pane.cursor1.pos)
      return
    end
  end
  -- finally, scan the cursor pane from bottom until cursor
  local pane = Surface[Cursor_pane.col][Cursor_pane.row]
  local old_cursor = pane.cursor1
  pane.cursor1 = {line=#pane.lines, pos=#pane.lines[#pane.lines].data+1}
  if search_previous_in_pane(pane) then
    if Text.lt1(old_cursor, pane.cursor1) then
      return
    end
  end
  -- nothing found
  pane.cursor1 = old_cursor_in_cursor_pane
end
-- returns whether it found an occurrence
function search_previous_in_pane(pane)
  pane.search_term = Display_settings.search_term
  pane.search_text = Display_settings.search_text
  pane.search_backup = {cursor={line=pane.cursor1.line, pos=pane.cursor1.pos}, screen_top={line=pane.screen_top1.line, pos=pane.screen_top1.pos}}
  for i=1,#pane.lines do
    if pane.line_cache[i] == nil then
      pane.line_cache[i] = {}
    end
  end
  if Text.search_previous(pane) then
    if Text.lt1(pane.cursor1, pane.search_backup.cursor) then
      -- select this occurrence
      return true
    end
    -- Otherwise cursor wrapped around. Skip this pane.
  end
  -- Clean up this pane before moving on to the previous one.
  pane.search_term = nil
  pane.search_text = nil
  pane.cursor1.line = pane.search_backup.cursor.line
  pane.cursor1.pos = pane.search_backup.cursor.pos
  pane.screen_top1.line = pane.search_backup.screen_top.line
  pane.screen_top1.pos = pane.search_backup.screen_top.pos
  pane.search_backup = nil

        pane.cursor1.pos = pane.cursor1.pos-1