To execute efficient document retrieval by excluding any useless input/output data in retrieval processing when discriminating different notation characters or not discriminating them.
This device is provided with a character string conversion part for converting respective characters in an inputted retrieval keyword into character codes exclusively for one character or character codes assigned to the set of different notation characters based on different notation conditions to designate whether to identify or discriminate the different notation characters, a position information reading part for reading the occurrence position information of the respective character codes in a document to be retrieved by referring to a retrieval database, a collating part for collating the occurrence position information of the respective character codes with the character code column and a collation result outputting part for outputting the occurrence position information of the retrieval keyword based on the collation result.
YAMAGISHI YOSHINORI
KORI MITSUNORI
Konobu Kato
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