Evaluation of Regular Nonlinear Recursions by Deductive Database Techniques

Nonlinear recursion is one of the most challenging classes of logic programs for eecient evaluation in logic programming systems. We identify one popular class of nonlinear recur-sion, regular nonlinear recursion, and investigate its eecient implementation by a deductive database approach. The approach performs a detailed query binding analysis based on query information, constraint information and the structure of a recursion, selects an appropriate predicate evaluation order and generates an eecient query evaluation plan. Interesting query evaluation techniques, such as chain-following, chain-split, and constraint pushing, are developed for the eecient evaluation of diierent kinds of queries. Furthermore, the technique can be extended to the evaluation of regular nonlinear recursions in HiLog and F-logic programs. The study not only presents a method for the evaluation of regular nonlinear recursions in a declarative way but also demonstrates the power of the deductive database approach in the analysis and evaluation of sophisticated logic programs.