DROPS

Document

DOI: 10.4230/LIPIcs.FSCD.2026.33

Investigations on Higher-Order Infinitary Logic

Authors: Thomas Traversié, Olivier Hermant, and Marc Aiguier

Published in: LIPIcs, Volume 378, 11th International Conference on Formal Structures for Computation and Deduction (FSCD 2026)

Abstract

Higher-order logic and infinitary logic are two extensions of first-order logic that allow greater expressivity. Both features have not been investigated together yet. In this paper, we define a higher-order infinitary logic, based on an extension of simple type theory. The resulting logic features higher-order quantifiers, infinite conjunctions and infinite disjunctions. We establish results at both the syntactic and the semantic level. We introduce a sound notion of model, and we show a strong version of completeness that entails the cut-elimination theorem for natural deduction. Moreover, we prove an extension of Barr’s theorem, allowing us to constructivize classical proofs of a particular fragment of higher-order infinitary logic.

Cite as

Thomas Traversié, Olivier Hermant, and Marc Aiguier. Investigations on Higher-Order Infinitary Logic. In 11th International Conference on Formal Structures for Computation and Deduction (FSCD 2026). Leibniz International Proceedings in Informatics (LIPIcs), Volume 378, pp. 33:1-33:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)

Copy BibTex To Clipboard

@InProceedings{traversie_et_al:LIPIcs.FSCD.2026.33,
  author =	{Traversi\'{e}, Thomas and Hermant, Olivier and Aiguier, Marc},
  title =	{{Investigations on Higher-Order Infinitary Logic}},
  booktitle =	{11th International Conference on Formal Structures for Computation and Deduction (FSCD 2026)},
  pages =	{33:1--33:19},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-433-8},
  ISSN =	{1868-8969},
  year =	{2026},
  volume =	{378},
  editor =	{Pfenning, Frank},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSCD.2026.33},
  URN =		{urn:nbn:de:0030-drops-263835},
  doi =		{10.4230/LIPIcs.FSCD.2026.33},
  annote =	{Keywords: Infinitary logic, higher-order logic, cut elimination, constructivization}
}

Document

DOI: 10.4230/LIPIcs.FSCD.2025.34

Monad Translations for Higher-Order Logic

Authors: Thomas Traversié

Published in: LIPIcs, Volume 337, 10th International Conference on Formal Structures for Computation and Deduction (FSCD 2025)

Abstract

Classical logic can be embedded into intuitionistic logic by inserting double negations in formulas. Several translations generalize this idea by using monad operators instead of double negations. They eliminate particular axioms, for instance the principle of excluded middle or the principle of explosion, and therefore can be used to embed classical logic into intuitionistic logic or intuitionistic logic into minimal logic. Such translations have been defined for first-order logic. In this paper, we define a translation, parameterized by monad operators, for higher-order logic. In particular, the property that any formula and its translation are equivalent in the presence of the eliminated axiom holds under functional extensionality and propositional extensionality. We apply this translation to embed higher-order classical (respectively intuitionistic) logic into higher-order intuitionistic (respectively minimal) logic. By adapting Friedman’s trick, we show that coherent formulas correspond to a constructive fragment of higher-order classical logic, meaning that we can transform classical proofs into intuitionistic proofs without modifying the proven statements.

Cite as

Thomas Traversié. Monad Translations for Higher-Order Logic. In 10th International Conference on Formal Structures for Computation and Deduction (FSCD 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 337, pp. 34:1-34:14, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)

Copy BibTex To Clipboard

@InProceedings{traversie:LIPIcs.FSCD.2025.34,
  author =	{Traversi\'{e}, Thomas},
  title =	{{Monad Translations for Higher-Order Logic}},
  booktitle =	{10th International Conference on Formal Structures for Computation and Deduction (FSCD 2025)},
  pages =	{34:1--34:14},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-374-4},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{337},
  editor =	{Fern\'{a}ndez, Maribel},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSCD.2025.34},
  URN =		{urn:nbn:de:0030-drops-236495},
  doi =		{10.4230/LIPIcs.FSCD.2025.34},
  annote =	{Keywords: Higher-order logic, Intuitionistic logic, Kuroda’s translation, Monad}
}

Search Results

Documents authored by Traversié, Thomas

Investigations on Higher-Order Infinitary Logic

Abstract

Cite as

Monad Translations for Higher-Order Logic

Abstract

Cite as

Thanks for your feedback!

Could not send message