Logical Algorithms meets CHR: A meta-complexity result for Constraint Handling Rules with rule priorities

摘要

This paper investigates the relationship between the Logical Algorithms (LA) language of Ganzinger and McAllester and Constraint Handling Rules (CHR). We present a translation schema from LA to CHR~(rp): CHR with rule priorities, and show that the meta-complexity theorem for LA can be applied to a subset of CHR~(rp) via inverse translation. Inspired by the high-level implementation proposal for Logical Algorithm by Ganzinger and McAllester and based on a new scheduling algorithm, we propose an alternative implementation for CHR~(rp) that gives strong complexity guarantees and results in a new and accurate meta-complexity theorem for CHR~(rp). It is furthermore shown that the translation from Logical Algorithms to CHR~(rp) combined with the new CHR~(rp) implementation satisfies the required complexity for the Logical Algorithms meta-complexity result to hold.