13. Document processing apparatus comprising: means for inputting data representing documents and titles respectively associated with the documents by a plurality of key input operations; means for storing characters comprising documents and titles associated therewith in a random order, said storing means having a field for numbering, an evaluation value obtained by comparing each of the titles being stored in the field to obtain a language dictionary word arrangement of the titles and a currently displayed title being changed to a title to be displayed with other titles in a reverse sequence or in a forward sequence in accordance with the stored evaluation value; means for displaying a portion of the titles stored in said storing means; means for generating a display control signal; means for assigning the titles stored in said storing means an order by comparing each of the titles and generating the evaluation value for each of the titles; order storing means for storing the order assigned by said assigning means; and control means responsive to the stored order in said order storing means for controlling said displaying means to sequentially display each of the titles stored in said storing means in accordance with the order assigned thereto by said assigning means by changing at least one displayed title to the following displayed title, so that one character of one displayed title corresponds to a first character of a next displayed title, regardless of the length of the titles.
18. Document processing apparatus according to claim 13, further comprising call-up means for calling up a text corresponding to a title displayed on said display means.