12. The method of claim 1 , further comprising: before receiving the third user input in the selection area indicating the selected symbolic element, receiving a fourth user input in the selection area at an extreme location of the selection area; and adding a new individual symbolic element to the selection area and removing, from the selection area, an old individual symbolic element from the second target range based on the fourth user input.
14. The method of claim 12 , wherein the fourth user input is located at a left extreme of the selection area, and the new individual symbolic element is a character before a first symbolic element in the second target range and the old individual symbolic element is a last symbolic element in the second target range.