Stubborness: A Possible Enhancement for Backjumping and Nogood Recording
نویسندگان
چکیده
The Conflict directed Backjumping (CBJ) algorithm attempts to reduce the number of nodes visited within the constraint satisfaction problem by analyzing failures. The Nogood Recording (NR ) algorithms incorporate, during the search, part of the results of these analyzes as constraints in the CSP solved itself. In both cases, failures are the basic information used to increase efficiency. It is shown how artificially augmenting the number of failures may lead to notable improvements in efficiency.
منابع مشابه
The Effect of Nogood Recording in MAC-CBJ SAT Algorithms
Propositional Satisfiability (SAT) solvers have been the subject of remarkable improvements in the last few years. Currently, the most successful SAT solvers share a number of similarities, being based on backtrack search, applying unit propagation, and incorporating a number of additional search reduction techniques. Most, if not all, of the search reduction techniques used by state-of-the-art...
متن کاملA generic bounded backtracking framework for solving CSPs
This paper introduces a new generic backtracking framework for solving CSPs. This scheme exploits semantic and topological properties of the constraint network to produce goods and nogoods. It is based on a set of separators of the constraint graph and several procedures adjustable to exploit heuristics, filtering, backjumping techniques, classical nogood recording, topological (no)good recordi...
متن کاملThe Effect of Nogood Recording in DPLL-CBJ SAT Algorithms
Propositional Satisfiability (SAT) solvers have been the subject of remarkable improvements in the last few years. Currently, the most successful SAT solvers share a number of similarities, being based on backtrack search, applying unit propagation, and incorporating a number of additional search pruning techniques. Most, if not all, of the search reduction techniques used by state-of-the-art S...
متن کاملUnrestricted Nogood Recording in CSP Search
Recently spectacular improvements in the performance of SAT solvers have been achieved through nogood recording (clause learning). In the CSP literature, on the other hand, nogood recording remains a fairly minor technique for improving backtracking algorithms. In this paper we demonstrate how recent nogood recording techniques from SAT can be generalized to CSPs. The result is a significant en...
متن کاملUnrestricted Nogood Recording and Restarting in CSP search
Nogood recording is a known technique for pruning the search tree in backtracking search. Unfortunately, unrestricted nogood recording carries an overhead which has lead to the development of restricted forms of it. In this paper, we show how recent developments in the SAT literature can be applied in CSPs to facilitate unrestricted nogood recording. This in turn allows us to effectively use re...
متن کامل