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Documents authored by Naaf, Matthias

Document
DOI: 10.4230/OASIcs.Tannen.3
Semiring Provenance in the Infinite

Authors: Sophie Brinke, Erich Grädel, Lovro Mrkonjić, and Matthias Naaf

Published in: OASIcs, Volume 119, The Provenance of Elegance in Computation - Essays Dedicated to Val Tannen (2024)

Abstract
Semiring provenance evaluates database queries or logical statements not just by true or false but by values in some commutative semiring. This permits to track which combinations of atomic facts are responsible for the truth of a statement, and to derive further information, for instance concerning costs, confidence scores, number of proof trees, or access levels to protected data. The focus of this approach, proposed and developed to a large extent by Val Tannen and his collaborators, has first been on (positive) database query languages, but has later been extended, again in collaboration with Val, to a systematic semiring semantics for first-order logic (and other logical systems), as well as to a method for the strategy analysis of games. So far, semiring provenance has been studied for finite structures. To extend the semiring provenance approach for first-order logic to infinite domains, the semirings need to be equipped with addition and multiplication operators over infinite collections of values. This needs solid algebraic foundations, and we study here the necessary and desirable properties of semirings with infinitary operations to provide a well-defined and informative provenance analysis over infinite domains. We show that, with suitable definitions for such infinitary semiring, large parts of the theory of semiring provenance can be succesfully generalised to infinite structures.
Cite as

Sophie Brinke, Erich Grädel, Lovro Mrkonjić, and Matthias Naaf. Semiring Provenance in the Infinite. In The Provenance of Elegance in Computation - Essays Dedicated to Val Tannen. Open Access Series in Informatics (OASIcs), Volume 119, pp. 3:1-3:26, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

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@InProceedings{brinke_et_al:OASIcs.Tannen.3,
  author =	{Brinke, Sophie and Gr\"{a}del, Erich and Mrkonji\'{c}, Lovro and Naaf, Matthias},
  title =	{{Semiring Provenance in the Infinite}},
  booktitle =	{The Provenance of Elegance in Computation - Essays Dedicated to Val Tannen},
  pages =	{3:1--3:26},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-95977-320-1},
  ISSN =	{2190-6807},
  year =	{2024},
  volume =	{119},
  editor =	{Amarilli, Antoine and Deutsch, Alin},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.Tannen.3},
  URN =		{urn:nbn:de:0030-drops-200997},
  doi =		{10.4230/OASIcs.Tannen.3},
  annote =	{Keywords: Semiring semantics, first-order logic, semirings with infinitary operations}
}
Document
DOI: 10.4230/LIPIcs.MFCS.2023.20
Locality Theorems in Semiring Semantics

Authors: Clotilde Bizière, Erich Grädel, and Matthias Naaf

Published in: LIPIcs, Volume 272, 48th International Symposium on Mathematical Foundations of Computer Science (MFCS 2023)

Abstract
Semiring semantics of first-order logic generalises classical Boolean semantics by permitting truth values from a commutative semiring, which can model information such as costs or access restrictions. This raises the question to what extent classical model-theoretic properties still apply, and how this depends on the algebraic properties of the semiring. In this paper, we study this question for the classical locality theorems due to Hanf and Gaifman. We prove that Hanf’s locality theorem generalises to all semirings with idempotent operations, but fails for many non-idempotent semirings. We then consider Gaifman normal forms and show that for formulae with free variables, Gaifman’s theorem does not generalise beyond the Boolean semiring. Also for sentences, it fails in the natural semiring and the tropical semiring. Our main result, however, is a constructive proof of the existence of Gaifman normal forms for min-max and lattice semirings. The proof implies a stronger version of Gaifman’s classical theorem in Boolean semantics: every sentence has a Gaifman normal form which does not add negations.
Cite as

Clotilde Bizière, Erich Grädel, and Matthias Naaf. Locality Theorems in Semiring Semantics. In 48th International Symposium on Mathematical Foundations of Computer Science (MFCS 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 272, pp. 20:1-20:15, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)

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@InProceedings{biziere_et_al:LIPIcs.MFCS.2023.20,
  author =	{Bizi\`{e}re, Clotilde and Gr\"{a}del, Erich and Naaf, Matthias},
  title =	{{Locality Theorems in Semiring Semantics}},
  booktitle =	{48th International Symposium on Mathematical Foundations of Computer Science (MFCS 2023)},
  pages =	{20:1--20:15},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-292-1},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{272},
  editor =	{Leroux, J\'{e}r\^{o}me and Lombardy, Sylvain and Peleg, David},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2023.20},
  URN =		{urn:nbn:de:0030-drops-185546},
  doi =		{10.4230/LIPIcs.MFCS.2023.20},
  annote =	{Keywords: Semiring semantics, Locality, First-order logic}
}
Document
DOI: 10.4230/DagRep.12.2.1
Logic and Random Discrete Structures (Dagstuhl Seminar 22061)

Authors: Erich Grädel, Phokion G. Kolaitis, Marc Noy, and Matthias Naaf

Published in: Dagstuhl Reports, Volume 12, Issue 2 (2022)

Abstract
This report documents the program and the outcomes of Dagstuhl Seminar 22061 "Logic and Random Discrete Structures". The main topic of this seminar has been the analysis of large random discrete structures, such as trees, graphs, or permutations, from the perspective of mathematical logic. It has brought together both experts and junior researchers from a number of different areas where logic and random structures play a role, with the goal to establish new connections between such areas and to encourage interactions between foundational research and different application areas, including probabilistic databases.
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Erich Grädel, Phokion G. Kolaitis, Marc Noy, and Matthias Naaf. Logic and Random Discrete Structures (Dagstuhl Seminar 22061). In Dagstuhl Reports, Volume 12, Issue 2, pp. 1-16, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)

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@Article{gradel_et_al:DagRep.12.2.1,
  author =	{Gr\"{a}del, Erich and Kolaitis, Phokion G. and Noy, Marc and Naaf, Matthias},
  title =	{{Logic and Random Discrete Structures (Dagstuhl Seminar 22061)}},
  pages =	{1--16},
  journal =	{Dagstuhl Reports},
  ISSN =	{2192-5283},
  year =	{2022},
  volume =	{12},
  number =	{2},
  editor =	{Gr\"{a}del, Erich and Kolaitis, Phokion G. and Noy, Marc and Naaf, Matthias},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagRep.12.2.1},
  URN =		{urn:nbn:de:0030-drops-169295},
  doi =		{10.4230/DagRep.12.2.1},
  annote =	{Keywords: combinatorics, complexity theory, logic, random structures, probabilistic databases}
}
Document
DOI: 10.4230/LIPIcs.CSL.2021.17
Semiring Provenance for Fixed-Point Logic

Authors: Katrin M. Dannert, Erich Grädel, Matthias Naaf, and Val Tannen

Published in: LIPIcs, Volume 183, 29th EACSL Annual Conference on Computer Science Logic (CSL 2021)

Abstract
Semiring provenance is a successful approach, originating in database theory, to providing detailed information on how atomic facts combine to yield the result of a query. In particular, general provenance semirings of polynomials or formal power series provide precise descriptions of the evaluation strategies or "proof trees" for the query. By evaluating these descriptions in specific application semirings, one can extract practical information for instance about the confidence of a query or the cost of its evaluation. This paper develops semiring provenance for very general logical languages featuring the full interaction between negation and fixed-point inductions or, equivalently, arbitrary interleavings of least and greatest fixed points. This also opens the door to provenance analysis applications for modal μ-calculus and temporal logics, as well as for finite and infinite model-checking games. Interestingly, the common approach based on Kleene’s Fixed-Point Theorem for ω-continuous semirings is not sufficient for these general languages. We show that an adequate framework for the provenance analysis of full fixed-point logics is provided by semirings that are (1) fully continuous, and (2) absorptive. Full continuity guarantees that provenance values of least and greatest fixed-points are well-defined. Absorptive semirings provide a symmetry between least and greatest fixed-points and make sure that provenance values of greatest fixed points are informative. We identify semirings of generalized absorptive polynomials S^{∞}[X] and prove universal properties that make them the most general appropriate semirings for our framework. These semirings have the further property of being (3) chain-positive, which is responsible for having truth-preserving interpretations that give non-zero values to all true formulae. We relate the provenance analysis of fixed-point formulae with provenance values of plays and strategies in the associated model-checking games. Specifically, we prove that the provenance value of a fixed point formula gives precise information on the evaluation strategies in these games.
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Katrin M. Dannert, Erich Grädel, Matthias Naaf, and Val Tannen. Semiring Provenance for Fixed-Point Logic. In 29th EACSL Annual Conference on Computer Science Logic (CSL 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 183, pp. 17:1-17:22, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)

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@InProceedings{dannert_et_al:LIPIcs.CSL.2021.17,
  author =	{Dannert, Katrin M. and Gr\"{a}del, Erich and Naaf, Matthias and Tannen, Val},
  title =	{{Semiring Provenance for Fixed-Point Logic}},
  booktitle =	{29th EACSL Annual Conference on Computer Science Logic (CSL 2021)},
  pages =	{17:1--17:22},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-175-7},
  ISSN =	{1868-8969},
  year =	{2021},
  volume =	{183},
  editor =	{Baier, Christel and Goubault-Larrecq, Jean},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CSL.2021.17},
  URN =		{urn:nbn:de:0030-drops-134518},
  doi =		{10.4230/LIPIcs.CSL.2021.17},
  annote =	{Keywords: Finite Model Theory, Semiring Provenance, Absorptive Semirings, Fixed-Point Logics}
}
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