A New Variable Ordering for In-Processing Bounded Variable Elimination in SAT Solvers
Abstract
Bounded Variable Elimination (BVE) is an important Boolean formula simplification technique in which the variable ordering is crucial. We define a new variable ordering based on variable activity, called ESA (variable Elimination Scheduled by Activity), for in-processing BVE in Conflict-Driven Clause Learning (CDCL) SAT solvers, and incorporate it into several state-of-the-art CDCL SAT solvers. Experimental results show that the new ESA ordering consistently makes these solvers solve more instances on the benchmark set including all the 5675 instances used in the Crafted, Application and Main tracks of all SAT Competitions up to 2022. In particular, one of these solvers with ESA, Kissat_MAB_ESA, won the Anniversary track of the SAT Competition 2022. The behaviour of ESA and the reason of its effectiveness are also analyzed.
Cite
Text
Li et al. "A New Variable Ordering for In-Processing Bounded Variable Elimination in SAT Solvers." International Joint Conference on Artificial Intelligence, 2023. doi:10.24963/IJCAI.2023/220Markdown
[Li et al. "A New Variable Ordering for In-Processing Bounded Variable Elimination in SAT Solvers." International Joint Conference on Artificial Intelligence, 2023.](https://mlanthology.org/ijcai/2023/li2023ijcai-new/) doi:10.24963/IJCAI.2023/220BibTeX
@inproceedings{li2023ijcai-new,
title = {{A New Variable Ordering for In-Processing Bounded Variable Elimination in SAT Solvers}},
author = {Li, Shuolin and Li, Chu-Min and Luo, Mao and Coll, Jordi and Habet, Djamal and Manyà, Felip},
booktitle = {International Joint Conference on Artificial Intelligence},
year = {2023},
pages = {1979-1987},
doi = {10.24963/IJCAI.2023/220},
url = {https://mlanthology.org/ijcai/2023/li2023ijcai-new/}
}