4. The system according to claim 3 , wherein the LWD has a plurality of classes, each of the classes containing long words having a first letter corresponding to predetermined keys of the keyboard.
4. The system according to claim 3 , wherein the LWD has a plurality of classes, each of the classes containing long words having a first letter corresponding to predetermined keys of the keyboard. 9. The system according to claim 4 , further comprising determining possible intermediate letter candidates of the long word according to a partial trajectory.