Abstract
We investigate how to extract alternating time bounds from ‘focussed’ proofs, treating non-invertible rule phases as nondeterministic computation and invertible rule phases as co-nondeterministic computation. We refine the usual presentation of focussing to account for deterministic computations in proof search, which correspond to invertible rules that do not branch, more faithfully associating phases of focussed proof search to their alternating time complexity. As our main result, we give a focussed system for MALLw (MALL with weakening) with encodings to and from true quantified Boolean formulas (QBFs): in one direction we encode QBF satisfiability and in the other we encode focussed proof search. Moreover we show that the composition of the two encodings preserves quantifier alternation, yielding natural fragments of MALLw complete for each level of the polynomial hierarchy. This refines the well-known result that MALLw is PSPACE-complete.
Original language | English |
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Title of host publication | Automated reasoning : 9th International Joint Conference, IJCAR 2018 Held as Part of the Federated Logic Conference, FloC 2018 Oxford, UK, July 14–17, 2018 Proceedings |
Editors | Didier Galmiche, Stephan Schulz, Roberto Sebastiani |
Publisher | Springer |
Publication date | 30 Jun 2018 |
Pages | 689-705 |
Chapter | 45 |
ISBN (Print) | 978-3-319-94204-9 |
ISBN (Electronic) | 978-3-319-94205-6 |
DOIs | |
Publication status | Published - 30 Jun 2018 |
Event | 9th International Joint Conference on Automated Reasoning - Oxford, United Kingdom Duration: 14 Jul 2018 → 17 Jul 2018 |
Conference
Conference | 9th International Joint Conference on Automated Reasoning |
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Country/Territory | United Kingdom |
City | Oxford |
Period | 14/07/2018 → 17/07/2018 |
Series | Lecture Notes in Computer Science |
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Volume | 10900 |
ISSN | 0302-9743 |