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A generalized method for proving polynomial calculus degree lower bounds

Mikša, Mladen and Nordström, Jakob LU (2015) 30th Conference on Computational Complexity, CCC 2015 In Leibniz International Proceedings in Informatics, LIPIcs 33. p.467-487
Abstract

We study the problem of obtaining lower bounds for polynomial calculus (PC) and polynomial calculus resolution (PCR) on proof degree, and hence by [Impagliazzo et al. '99] also on proof size. [Alekhnovich and Razborov'03] established that if the clause-variable incidence graph of a CNF formula F is a good enough expander, then proving that F is unsatisfiable requires high PC/PCR degree. We further develop the techniques in [AR03] to show that if one can "cluster" clauses and variables in a way that "respects the structure" of the formula in a certain sense, then it is sufficient that the incidence graph of this clustered version is an expander. As a corollary of this, we prove that the functional pigeonhole principle (FPHP) formulas... (More)

We study the problem of obtaining lower bounds for polynomial calculus (PC) and polynomial calculus resolution (PCR) on proof degree, and hence by [Impagliazzo et al. '99] also on proof size. [Alekhnovich and Razborov'03] established that if the clause-variable incidence graph of a CNF formula F is a good enough expander, then proving that F is unsatisfiable requires high PC/PCR degree. We further develop the techniques in [AR03] to show that if one can "cluster" clauses and variables in a way that "respects the structure" of the formula in a certain sense, then it is sufficient that the incidence graph of this clustered version is an expander. As a corollary of this, we prove that the functional pigeonhole principle (FPHP) formulas require high PC/PCR degree when restricted to constant-degree expander graphs. This answers an open question in [Razborov'02], and also implies that the standard CNF encoding of the FPHP formulas require exponential proof size in polynomial calculus resolution. Thus, while Onto-FPHP formulas are easy for polynomial calculus, as shown in [Riis'93], both FPHP and Onto-PHP formulas are hard even when restricted to bounded-degree expanders.

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Please use this url to cite or link to this publication:
author
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publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Degree, Functional pigeonhole principle, Lower bound, PCR, Polynomial calculus, Polynomial calculus resolution, Proof complexity, Size
host publication
30th Conference on Computational Complexity, CCC 2015
series title
Leibniz International Proceedings in Informatics, LIPIcs
editor
Zuckerman, David
volume
33
pages
21 pages
publisher
Schloss Dagstuhl - Leibniz-Zentrum für Informatik
conference name
30th Conference on Computational Complexity, CCC 2015
conference location
Portland, United States
conference dates
2015-06-17 - 2015-06-19
external identifiers
  • scopus:84958256296
ISSN
1868-8969
ISBN
9783939897811
DOI
10.4230/LIPIcs.CCC.2015.467
language
English
LU publication?
no
id
3fbb654b-fa15-4aa8-940f-9ce1af87d91e
date added to LUP
2020-12-18 22:23:04
date last changed
2022-04-26 22:58:01
@inproceedings{3fbb654b-fa15-4aa8-940f-9ce1af87d91e,
  abstract     = {{<p>We study the problem of obtaining lower bounds for polynomial calculus (PC) and polynomial calculus resolution (PCR) on proof degree, and hence by [Impagliazzo et al. '99] also on proof size. [Alekhnovich and Razborov'03] established that if the clause-variable incidence graph of a CNF formula F is a good enough expander, then proving that F is unsatisfiable requires high PC/PCR degree. We further develop the techniques in [AR03] to show that if one can "cluster" clauses and variables in a way that "respects the structure" of the formula in a certain sense, then it is sufficient that the incidence graph of this clustered version is an expander. As a corollary of this, we prove that the functional pigeonhole principle (FPHP) formulas require high PC/PCR degree when restricted to constant-degree expander graphs. This answers an open question in [Razborov'02], and also implies that the standard CNF encoding of the FPHP formulas require exponential proof size in polynomial calculus resolution. Thus, while Onto-FPHP formulas are easy for polynomial calculus, as shown in [Riis'93], both FPHP and Onto-PHP formulas are hard even when restricted to bounded-degree expanders.</p>}},
  author       = {{Mikša, Mladen and Nordström, Jakob}},
  booktitle    = {{30th Conference on Computational Complexity, CCC 2015}},
  editor       = {{Zuckerman, David}},
  isbn         = {{9783939897811}},
  issn         = {{1868-8969}},
  keywords     = {{Degree; Functional pigeonhole principle; Lower bound; PCR; Polynomial calculus; Polynomial calculus resolution; Proof complexity; Size}},
  language     = {{eng}},
  month        = {{06}},
  pages        = {{467--487}},
  publisher    = {{Schloss Dagstuhl - Leibniz-Zentrum für Informatik}},
  series       = {{Leibniz International Proceedings in Informatics, LIPIcs}},
  title        = {{A generalized method for proving polynomial calculus degree lower bounds}},
  url          = {{http://dx.doi.org/10.4230/LIPIcs.CCC.2015.467}},
  doi          = {{10.4230/LIPIcs.CCC.2015.467}},
  volume       = {{33}},
  year         = {{2015}},
}