4. A data processing apparatus according to claim 3 , further comprising: means for allowing the user to input an instruction to add new data to the data thus integrated and presented by said presenting means, and an instruction to remove a part of the data; and means for adding or removing the information, which is stored in the first data file and which serves as a key, according to the instruction thus input.
4. A data processing apparatus according to claim 3 , further comprising: means for allowing the user to input an instruction to add new data to the data thus integrated and presented by said presenting means, and an instruction to remove a part of the data; and means for adding or removing the information, which is stored in the first data file and which serves as a key, according to the instruction thus input. 5. A data processing apparatus according to claim 4 , further comprising: means for allowing the user to input an instruction to edit the data thus integrated and presented by said presenting means; and means for modifying the second data file that stores the data, according to the editing instruction.