Abstract
A crucial operation of saturation theorem provers is deletion of subsumed formulas. Designers of proof calculi, however, usually discuss this only informally, and the rare formal expositions tend to be clumsy. This is because the equivalence of dynamic and static refutational completeness holds only for derivations where all deleted formulas are redundant, but the standard notion of redundancy is too weak: A clause C does not make an instance Cσ redundant. We present a framework for formal refutational completeness proofs of abstract provers that implement saturation calculi, such as ordered resolution and superposition. The framework modularly extends redundancy criteria derived via a familiar ground-to-nonground lifting. It allows us to extend redundancy criteria so that they cover subsumption, and also to model entire prover architectures so that the static refutational completeness of a calculus immediately implies the dynamic refutational completeness of a prover implementing the calculus within, for instance, an Otter or DISCOUNT loop. Our framework is mechanized in Isabelle/HOL.
Original language | English |
---|---|
Pages (from-to) | 499-539 |
Number of pages | 41 |
Journal | Journal of Automated Reasoning |
Volume | 66 |
Issue number | 4 |
Early online date | 7 Jun 2022 |
DOIs | |
Publication status | Published - Nov 2022 |
Bibliographical note
Funding Information:We thank Alexander Bentkamp for discussions about prover architectures for higher-order logic and for feedback from instantiating the framework, especially concerning Theorem 50. We thank Mathias Fleury and Christian Sternagel for their help with the Isabelle development. Finally, we thank Gabriel Ebner, Robert Lewis, Visa Nummelin, Dmitriy Traytel, and the anonymous reviewers for their comments and suggestions. Blanchette’s research has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 713999, Matryoshka). He also benefited from the Netherlands Organization for Scientific Research (NWO) Incidental Financial Support scheme and he has received funding from the NWO under the Vidi program (project No. 016.Vidi.189.037, Lean Forward).
Funding Information:
We thank Alexander Bentkamp for discussions about prover architectures for higher-order logic and for feedback from instantiating the framework, especially concerning Theorem . We thank Mathias Fleury and Christian Sternagel for their help with the Isabelle development. Finally, we thank Gabriel Ebner, Robert Lewis, Visa Nummelin, Dmitriy Traytel, and the anonymous reviewers for their comments and suggestions. Blanchette’s research has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 713999, Matryoshka). He also benefited from the Netherlands Organization for Scientific Research (NWO) Incidental Financial Support scheme and he has received funding from the NWO under the Vidi program (project No. 016.Vidi.189.037, Lean Forward).
Publisher Copyright:
© 2022, The Author(s).
Funding
We thank Alexander Bentkamp for discussions about prover architectures for higher-order logic and for feedback from instantiating the framework, especially concerning Theorem 50. We thank Mathias Fleury and Christian Sternagel for their help with the Isabelle development. Finally, we thank Gabriel Ebner, Robert Lewis, Visa Nummelin, Dmitriy Traytel, and the anonymous reviewers for their comments and suggestions. Blanchette’s research has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 713999, Matryoshka). He also benefited from the Netherlands Organization for Scientific Research (NWO) Incidental Financial Support scheme and he has received funding from the NWO under the Vidi program (project No. 016.Vidi.189.037, Lean Forward). We thank Alexander Bentkamp for discussions about prover architectures for higher-order logic and for feedback from instantiating the framework, especially concerning Theorem . We thank Mathias Fleury and Christian Sternagel for their help with the Isabelle development. Finally, we thank Gabriel Ebner, Robert Lewis, Visa Nummelin, Dmitriy Traytel, and the anonymous reviewers for their comments and suggestions. Blanchette’s research has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 713999, Matryoshka). He also benefited from the Netherlands Organization for Scientific Research (NWO) Incidental Financial Support scheme and he has received funding from the NWO under the Vidi program (project No. 016.Vidi.189.037, Lean Forward).
Funders | Funder number |
---|---|
European Research Council | |
Mathias Fleury | |
Not added | 016.Vidi.189.037, 016 |
Horizon 2020 Framework Programme | 713999 |
Keywords
- Automated theorem proving
- Prover architectures
- Redundancy
- Resolution calculus
- Saturation
- Superposition calculus