DEFINING A DATA STRUCTURE FOR PATTERN MATCHING

An information processing method for defining a data structure for pattern matching, the method executed by an information processing apparatus, comprises generating, by the apparatus, an ordered tree structure by defining transition edges between nodes using, as transition conditions, respective constraints from one or more constraint patterns each including plural constraints; searching, by the apparatus, for a second substructure similar to a first substructure from a root node by determining a set relation between transition conditions of respective transition edges; and defining, by the apparatus, an additional transition link from a tail node of the second substructure to a child node at a tail end of the first substructure, the additional transition link adding a constraint to be met by an indeterminant identified from the set relation.