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Relating proof complexity measures and practical hardness of SAT

Järvisalo, Matti ; Matsliah, Arie ; Nordström, Jakob LU and Živný, Stanislav (2012) 18th International Conference on Principles and Practice of Constraint Programming, CP 2012 In Lecture Notes in Computer Science 7514. p.316-331
Abstract

Boolean satisfiability (SAT) solvers have improved enormously in performance over the last 10-15 years and are today an indispensable tool for solving a wide range of computational problems. However, our understanding of what makes SAT instances hard or easy in practice is still quite limited. A recent line of research in proof complexity has studied theoretical complexity measures such as length, width, and space in resolution, which is a proof system closely related to state-of-the-art conflict-driven clause learning (CDCL) SAT solvers. Although it seems like a natural question whether these complexity measures could be relevant for understanding the practical hardness of SAT instances, to date there has been very limited research on... (More)

Boolean satisfiability (SAT) solvers have improved enormously in performance over the last 10-15 years and are today an indispensable tool for solving a wide range of computational problems. However, our understanding of what makes SAT instances hard or easy in practice is still quite limited. A recent line of research in proof complexity has studied theoretical complexity measures such as length, width, and space in resolution, which is a proof system closely related to state-of-the-art conflict-driven clause learning (CDCL) SAT solvers. Although it seems like a natural question whether these complexity measures could be relevant for understanding the practical hardness of SAT instances, to date there has been very limited research on such possible connections. This paper sets out on a systematic study of the interconnections between theoretical complexity and practical SAT solver performance. Our main focus is on space complexity in resolution, and we report results from extensive experiments aimed at understanding to what extent this measure is correlated with hardness in practice. Our conclusion from the empirical data is that the resolution space complexity of a formula would seem to be a more fine-grained indicator of whether the formula is hard or easy than the length or width needed in a resolution proof. On the theory side, we prove a separation of general and tree-like resolution space, where the latter has been proposed before as a measure of practical hardness, and also show connections between resolution space and backdoor sets.

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Please use this url to cite or link to this publication:
author
; ; and
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
host publication
Principles and Practice of Constraint Programming : 18th International Conference, CP 2012, Proceedings - 18th International Conference, CP 2012, Proceedings
series title
Lecture Notes in Computer Science
volume
7514
pages
16 pages
publisher
Springer
conference name
18th International Conference on Principles and Practice of Constraint Programming, CP 2012
conference location
Quebec City, QC, Canada
conference dates
2012-10-08 - 2012-10-12
external identifiers
  • scopus:84868269243
ISSN
1611-3349
0302-9743
ISBN
9783642335570
DOI
10.1007/978-3-642-33558-7_25
language
English
LU publication?
no
id
e963a526-e865-4496-b714-8908a5d32342
date added to LUP
2020-12-18 22:26:32
date last changed
2025-04-04 14:26:14
@inproceedings{e963a526-e865-4496-b714-8908a5d32342,
  abstract     = {{<p>Boolean satisfiability (SAT) solvers have improved enormously in performance over the last 10-15 years and are today an indispensable tool for solving a wide range of computational problems. However, our understanding of what makes SAT instances hard or easy in practice is still quite limited. A recent line of research in proof complexity has studied theoretical complexity measures such as length, width, and space in resolution, which is a proof system closely related to state-of-the-art conflict-driven clause learning (CDCL) SAT solvers. Although it seems like a natural question whether these complexity measures could be relevant for understanding the practical hardness of SAT instances, to date there has been very limited research on such possible connections. This paper sets out on a systematic study of the interconnections between theoretical complexity and practical SAT solver performance. Our main focus is on space complexity in resolution, and we report results from extensive experiments aimed at understanding to what extent this measure is correlated with hardness in practice. Our conclusion from the empirical data is that the resolution space complexity of a formula would seem to be a more fine-grained indicator of whether the formula is hard or easy than the length or width needed in a resolution proof. On the theory side, we prove a separation of general and tree-like resolution space, where the latter has been proposed before as a measure of practical hardness, and also show connections between resolution space and backdoor sets.</p>}},
  author       = {{Järvisalo, Matti and Matsliah, Arie and Nordström, Jakob and Živný, Stanislav}},
  booktitle    = {{Principles and Practice of Constraint Programming : 18th International Conference, CP 2012, Proceedings}},
  isbn         = {{9783642335570}},
  issn         = {{1611-3349}},
  language     = {{eng}},
  pages        = {{316--331}},
  publisher    = {{Springer}},
  series       = {{Lecture Notes in Computer Science}},
  title        = {{Relating proof complexity measures and practical hardness of SAT}},
  url          = {{http://dx.doi.org/10.1007/978-3-642-33558-7_25}},
  doi          = {{10.1007/978-3-642-33558-7_25}},
  volume       = {{7514}},
  year         = {{2012}},
}