Approximate Pattern Matching in Shared-Forest

. We present a proposal intended to demonstrate the applicability of tabulation techniques to pattern recognition problems, when dealing with structures sharing some common parts. This work is motivated by the study of information retrieval for textual databases, using pattern matching as a basis for querying data. 1 Introduction One critical aspect of an information system that determines its eectiveness is indexing, that is, the representation of concepts to get a well formed data structure for search. Once this has been done, the system must dene a strategy in order to translate a query statement to the database and determine the information to be returned to the user. Until recently, indexing was accomplished by creating a bibliographic citation in a structured le that references the original text. This approach allows a reduction in time and space bounds, although the ability to nd information on a particular subject is limited by the system which creates index terms for that..