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Graphic representation of linear recursive rules
Author(s) -
Han Jia Liang,
Chen SuShing
Publication year - 1992
Publication title -
international journal of intelligent systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.291
H-Index - 87
eISSN - 1098-111X
pISSN - 0884-8173
DOI - 10.1002/int.4550070403
Subject(s) - graph , rewriting , null graph , mathematics , predicate (mathematical logic) , theoretical computer science , graph rewriting , computer science , discrete mathematics , algorithm , voltage graph , line graph , programming language
Recursive rules are important to deductive databases. A recursive rule may be compiled into expansions. In this article, the variable‐predicate graph (V‐P graph) based on the α‐graph by loannidis is developed to represent linear recursive function‐free rules and their expansions. A naming convention is used for variables and predicates in the V‐P graph so that all equivalent recursive rules may map into a unique V‐P graph. We propose a graphic construction method (g.c.m.) which derives V‐P graphs of expansions directly from the V‐P graph of the original rule. This graphic representation reveals some expansion properties not easy to obtain otherwise. We also propose a rule rewriting method in the context of deductive database so that constants, repeated distinguished variables, and/or repeated recursive variables may be removed from recursive rules.