Extending Decidable Existential Rules by Joining Acyclicity and Guardedness.

Existential rules, i.e. Datalog extended with existential quantifiers in rule heads, are currently studied under a variety of names such as Datalog+/-, ∀∃-rules, and tuple-generating dependencies. The renewed interest in this formalism is fuelled by a wealth of recently discovered language fragments...

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Main Authors: Krötzsch, M, Rudolph, S
Other Authors: Walsh, T
Format: Conference item
Published: IJCAI/AAAI 2011
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author Krötzsch, M
Rudolph, S
author2 Walsh, T
author_facet Walsh, T
Krötzsch, M
Rudolph, S
author_sort Krötzsch, M
collection OXFORD
description Existential rules, i.e. Datalog extended with existential quantifiers in rule heads, are currently studied under a variety of names such as Datalog+/-, ∀∃-rules, and tuple-generating dependencies. The renewed interest in this formalism is fuelled by a wealth of recently discovered language fragments for which query answering is decidable. This paper extends and consolidates two of the main approaches in this field - acyclicity and guardedness - by providing (1) complexity-preserving generalisations of weakly acyclic and weakly (frontier-)guarded rules, and (2) a novel formalism of glut-(frontier-)guarded rules that subsumes both. This builds on an insight that acyclicity can be used to extend any existential rule language while retaining decidability. Besides decidability, combined query complexities are established in all cases.
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spelling oxford-uuid:f466b81f-eaa1-47af-8863-e97df84699682022-03-27T12:19:30ZExtending Decidable Existential Rules by Joining Acyclicity and Guardedness.Conference itemhttp://purl.org/coar/resource_type/c_5794uuid:f466b81f-eaa1-47af-8863-e97df8469968Symplectic Elements at OxfordIJCAI/AAAI2011Krötzsch, MRudolph, SWalsh, TExistential rules, i.e. Datalog extended with existential quantifiers in rule heads, are currently studied under a variety of names such as Datalog+/-, ∀∃-rules, and tuple-generating dependencies. The renewed interest in this formalism is fuelled by a wealth of recently discovered language fragments for which query answering is decidable. This paper extends and consolidates two of the main approaches in this field - acyclicity and guardedness - by providing (1) complexity-preserving generalisations of weakly acyclic and weakly (frontier-)guarded rules, and (2) a novel formalism of glut-(frontier-)guarded rules that subsumes both. This builds on an insight that acyclicity can be used to extend any existential rule language while retaining decidability. Besides decidability, combined query complexities are established in all cases.
spellingShingle Krötzsch, M
Rudolph, S
Extending Decidable Existential Rules by Joining Acyclicity and Guardedness.
title Extending Decidable Existential Rules by Joining Acyclicity and Guardedness.
title_full Extending Decidable Existential Rules by Joining Acyclicity and Guardedness.
title_fullStr Extending Decidable Existential Rules by Joining Acyclicity and Guardedness.
title_full_unstemmed Extending Decidable Existential Rules by Joining Acyclicity and Guardedness.
title_short Extending Decidable Existential Rules by Joining Acyclicity and Guardedness.
title_sort extending decidable existential rules by joining acyclicity and guardedness
work_keys_str_mv AT krotzschm extendingdecidableexistentialrulesbyjoiningacyclicityandguardedness
AT rudolphs extendingdecidableexistentialrulesbyjoiningacyclicityandguardedness