Backdoors into heterogeneous classes of SAT and CSP

Backdoor sets represent clever reasoning shortcuts through the search space for SAT and CSP. By instantiating the backdoor variables one reduces the given instance to several easy instances that belong to a tractable class.The overall time needed to solve the instance is exponential in the size of t...

Full description

Bibliographic Details
Main Authors: Gaspers, S, Misra, N, Ordyniak, S, Szeider, S, Živný, S
Format: Conference item
Published: Association for the Advancement of Artificial Intelligence 2014
_version_ 1826272229543903232
author Gaspers, S
Misra, N
Ordyniak, S
Szeider, S
Živný, S
author_facet Gaspers, S
Misra, N
Ordyniak, S
Szeider, S
Živný, S
author_sort Gaspers, S
collection OXFORD
description Backdoor sets represent clever reasoning shortcuts through the search space for SAT and CSP. By instantiating the backdoor variables one reduces the given instance to several easy instances that belong to a tractable class.The overall time needed to solve the instance is exponential in the size of the backdoor set, hence it is a challenging problem to find a small backdoor set if one exists; over the last years this problem has been subject of intensive research. In this paper we extend the classical notion of a strong backdoor set by allowing that different instantiations of the backdoor variables result in instances that belong to different base classes; the union of the base classes forms a heterogeneous base class. Backdoor sets to heterogeneous base classes can be much smaller than backdoor sets to homogeneous ones, hence they are much more desirable but possibly harder to find. We draw a detailed complexity landscape for the problem of detecting strong backdoor sets into heterogeneous base classes for SAT and CSP. We provide algorithms that establish fixed-parameter tractability under natural parameterizations, and we contrast the tractability results with hardness results that pinpoint the theoretical limits. Our results apply to the current state-of-the-art of tractable classes of CSP and SAT that are definable by restricting the constraint language.
first_indexed 2024-03-06T22:09:14Z
format Conference item
id oxford-uuid:513b24b0-742c-43be-b0b6-2caf6d24a449
institution University of Oxford
last_indexed 2024-03-06T22:09:14Z
publishDate 2014
publisher Association for the Advancement of Artificial Intelligence
record_format dspace
spelling oxford-uuid:513b24b0-742c-43be-b0b6-2caf6d24a4492022-03-26T16:18:18ZBackdoors into heterogeneous classes of SAT and CSPConference itemhttp://purl.org/coar/resource_type/c_5794uuid:513b24b0-742c-43be-b0b6-2caf6d24a449Symplectic Elements at OxfordAssociation for the Advancement of Artificial Intelligence2014Gaspers, SMisra, NOrdyniak, SSzeider, SŽivný, SBackdoor sets represent clever reasoning shortcuts through the search space for SAT and CSP. By instantiating the backdoor variables one reduces the given instance to several easy instances that belong to a tractable class.The overall time needed to solve the instance is exponential in the size of the backdoor set, hence it is a challenging problem to find a small backdoor set if one exists; over the last years this problem has been subject of intensive research. In this paper we extend the classical notion of a strong backdoor set by allowing that different instantiations of the backdoor variables result in instances that belong to different base classes; the union of the base classes forms a heterogeneous base class. Backdoor sets to heterogeneous base classes can be much smaller than backdoor sets to homogeneous ones, hence they are much more desirable but possibly harder to find. We draw a detailed complexity landscape for the problem of detecting strong backdoor sets into heterogeneous base classes for SAT and CSP. We provide algorithms that establish fixed-parameter tractability under natural parameterizations, and we contrast the tractability results with hardness results that pinpoint the theoretical limits. Our results apply to the current state-of-the-art of tractable classes of CSP and SAT that are definable by restricting the constraint language.
spellingShingle Gaspers, S
Misra, N
Ordyniak, S
Szeider, S
Živný, S
Backdoors into heterogeneous classes of SAT and CSP
title Backdoors into heterogeneous classes of SAT and CSP
title_full Backdoors into heterogeneous classes of SAT and CSP
title_fullStr Backdoors into heterogeneous classes of SAT and CSP
title_full_unstemmed Backdoors into heterogeneous classes of SAT and CSP
title_short Backdoors into heterogeneous classes of SAT and CSP
title_sort backdoors into heterogeneous classes of sat and csp
work_keys_str_mv AT gasperss backdoorsintoheterogeneousclassesofsatandcsp
AT misran backdoorsintoheterogeneousclassesofsatandcsp
AT ordyniaks backdoorsintoheterogeneousclassesofsatandcsp
AT szeiders backdoorsintoheterogeneousclassesofsatandcsp
AT zivnys backdoorsintoheterogeneousclassesofsatandcsp