Check this out. Type a sentence. The place cursor in the middle of the sentence and hit delet 3-4 times. Now hit undo (Ctrl-z) to un-delete the characters. Once all characters have been undeleted hit redo (ctrl-y) to remove the characters again. Except this time, redo won't stop at the last action you took (the last character deleted by you) but instead will continue to delete the whole sentence.
