14 Search Results for "van Doorn, Floris"

Document
DOI: 10.4230/LIPIcs.ITP.2024.3
A Formal Analysis of Capacity Scaling Algorithms for Minimum Cost Flows

Authors: Mohammad Abdulaziz and Thomas Ammer

Published in: LIPIcs, Volume 309, 15th International Conference on Interactive Theorem Proving (ITP 2024)

Abstract
We present a formalisation of the correctness of algorithms to solve minimum-cost flow problems, in Isabelle/HOL. Two of the algorithms are based on the technique of scaling, most notably Orlin’s algorithm, which has the fastest running time for the problem of minimum-cost flow. Our work uncovered a number of complications in the proofs of the results we formalised, the resolution of which required significant effort. Our work is also the first to formally consider the problem of minimum-cost flows and, more generally, scaling algorithms.
Cite as

Mohammad Abdulaziz and Thomas Ammer. A Formal Analysis of Capacity Scaling Algorithms for Minimum Cost Flows. In 15th International Conference on Interactive Theorem Proving (ITP 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 309, pp. 3:1-3:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{abdulaziz_et_al:LIPIcs.ITP.2024.3,
  author =	{Abdulaziz, Mohammad and Ammer, Thomas},
  title =	{{A Formal Analysis of Capacity Scaling Algorithms for Minimum Cost Flows}},
  booktitle =	{15th International Conference on Interactive Theorem Proving (ITP 2024)},
  pages =	{3:1--3:19},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-337-9},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{309},
  editor =	{Bertot, Yves and Kutsia, Temur and Norrish, Michael},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2024.3},
  URN =		{urn:nbn:de:0030-drops-207316},
  doi =		{10.4230/LIPIcs.ITP.2024.3},
  annote =	{Keywords: Network Flows, Formal Verification, Combinatorial Optimisation}
}
Document
DOI: 10.4230/LIPIcs.ITP.2024.6
Towards Solid Abelian Groups: A Formal Proof of Nöbeling’s Theorem

Authors: Dagur Asgeirsson

Published in: LIPIcs, Volume 309, 15th International Conference on Interactive Theorem Proving (ITP 2024)

Abstract
Condensed mathematics, developed by Clausen and Scholze over the last few years, is a new way of studying the interplay between algebra and geometry. It replaces the concept of a topological space by a more sophisticated but better-behaved idea, namely that of a condensed set. Central to the theory are solid abelian groups and liquid vector spaces, analogues of complete topological groups. Nöbeling’s theorem, a surprising result from the 1960s about the structure of the abelian group of continuous maps from a profinite space to the integers, is a crucial ingredient in the theory of solid abelian groups; without it one cannot give any nonzero examples of solid abelian groups. We discuss a recently completed formalisation of this result in the Lean theorem prover, and give a more detailed proof than those previously available in the literature. The proof is somewhat unusual in that it requires induction over ordinals - a technique which has not previously been used to a great extent in formalised mathematics.
Cite as

Dagur Asgeirsson. Towards Solid Abelian Groups: A Formal Proof of Nöbeling’s Theorem. In 15th International Conference on Interactive Theorem Proving (ITP 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 309, pp. 6:1-6:17, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{asgeirsson:LIPIcs.ITP.2024.6,
  author =	{Asgeirsson, Dagur},
  title =	{{Towards Solid Abelian Groups: A Formal Proof of N\"{o}beling’s Theorem}},
  booktitle =	{15th International Conference on Interactive Theorem Proving (ITP 2024)},
  pages =	{6:1--6:17},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-337-9},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{309},
  editor =	{Bertot, Yves and Kutsia, Temur and Norrish, Michael},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2024.6},
  URN =		{urn:nbn:de:0030-drops-207347},
  doi =		{10.4230/LIPIcs.ITP.2024.6},
  annote =	{Keywords: Condensed mathematics, N\"{o}beling’s theorem, Lean, Mathlib, Interactive theorem proving}
}
Document
DOI: 10.4230/LIPIcs.ITP.2024.8
The Directed Van Kampen Theorem in Lean

Authors: Henning Basold, Peter Bruin, and Dominique Lawson

Published in: LIPIcs, Volume 309, 15th International Conference on Interactive Theorem Proving (ITP 2024)

Abstract
Directed topology augments the concept of a topological space with a notion of directed paths. This leads to a category of directed spaces, in which the morphisms are continuous maps respecting directed paths. Directed topology thereby enables an accurate representation of computation paths in concurrent systems that usually cannot be reversed. Even though ideas from algebraic topology have analogues in directed topology, the directedness drastically changes how spaces can be characterised. For instance, while an important homotopy invariant of a topological space is its fundamental groupoid, for directed spaces this has to be replaced by the fundamental category because directed paths are not necessarily reversible. In this paper, we present a Lean 4 formalisation of directed spaces and of a Van Kampen theorem for them, which allows the fundamental category of a directed space to be computed in terms of the fundamental categories of subspaces. Part of this formalisation is also a significant theory of directed spaces, directed homotopy theory and path coverings, which can serve as basis for future formalisations of directed topology. The formalisation in Lean can also be used in computer-assisted reasoning about the behaviour of concurrent systems that have been represented as directed spaces.
Cite as

Henning Basold, Peter Bruin, and Dominique Lawson. The Directed Van Kampen Theorem in Lean. In 15th International Conference on Interactive Theorem Proving (ITP 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 309, pp. 8:1-8:18, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{basold_et_al:LIPIcs.ITP.2024.8,
  author =	{Basold, Henning and Bruin, Peter and Lawson, Dominique},
  title =	{{The Directed Van Kampen Theorem in Lean}},
  booktitle =	{15th International Conference on Interactive Theorem Proving (ITP 2024)},
  pages =	{8:1--8:18},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-337-9},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{309},
  editor =	{Bertot, Yves and Kutsia, Temur and Norrish, Michael},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2024.8},
  URN =		{urn:nbn:de:0030-drops-207368},
  doi =		{10.4230/LIPIcs.ITP.2024.8},
  annote =	{Keywords: Lean, Directed Topology, Van Kampen Theorem, Directed Homotopy Theory, Formalised Mathematics}
}
Document
DOI: 10.4230/LIPIcs.ITP.2024.22
Distributed Parallel Build for the Isabelle Archive of Formal Proofs

Authors: Fabian Huch and Makarius Wenzel

Published in: LIPIcs, Volume 309, 15th International Conference on Interactive Theorem Proving (ITP 2024)

Abstract
Motivated by the continuously growing performance demands for the Isabelle Archive of Formal Proofs (AFP), we introduce distributed cluster computing to the Isabelle platform. Parallel build time on a single node has approached 4h-8h in recent years: by supporting multiple nodes, without shared memory nor shared file-systems, we target at a substantial speedup factor to get below the critical limit of 45min total elapsed time. Our distributed build tool is part of the regular Isabelle distribution, but specifically adapted to cope with the structure of projects seen in the AFP. In this work, we address two main challenges: (1) the distributed system architecture that has been implemented in Isabelle/Scala, and (2) the build schedule optimization problem for multi-threaded tasks on multiple compute nodes. We introduce a heuristic tuned to the typical AFP session structure, which can generate good schedules in a few seconds. We reached a total speedup factor of over 100, which is a milestone never before reached. Using this approach, we could build the Isabelle distribution in 8min 10s elapsed time, and the AFP in 35min 40s, or 1h 59min 13s including very slow sessions.
Cite as

Fabian Huch and Makarius Wenzel. Distributed Parallel Build for the Isabelle Archive of Formal Proofs. In 15th International Conference on Interactive Theorem Proving (ITP 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 309, pp. 22:1-22:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{huch_et_al:LIPIcs.ITP.2024.22,
  author =	{Huch, Fabian and Wenzel, Makarius},
  title =	{{Distributed Parallel Build for the Isabelle Archive of Formal Proofs}},
  booktitle =	{15th International Conference on Interactive Theorem Proving (ITP 2024)},
  pages =	{22:1--22:19},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-337-9},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{309},
  editor =	{Bertot, Yves and Kutsia, Temur and Norrish, Michael},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2024.22},
  URN =		{urn:nbn:de:0030-drops-207505},
  doi =		{10.4230/LIPIcs.ITP.2024.22},
  annote =	{Keywords: Interactive theorem proving, Isabelle, Archive of Formal Proofs, Theorem prover technology, Distributed computing, Schedule optimization}
}
Document
DOI: 10.4230/LIPIcs.ITP.2024.28
Lean Formalization of Completeness Proof for Coalition Logic with Common Knowledge

Authors: Kai Obendrauf, Anne Baanen, Patrick Koopmann, and Vera Stebletsova

Published in: LIPIcs, Volume 309, 15th International Conference on Interactive Theorem Proving (ITP 2024)

Abstract
Coalition Logic (CL) is a well-known formalism for reasoning about the strategic abilities of groups of agents in multi-agent systems. Coalition Logic with Common Knowledge (CLC) extends CL with operators from epistic logics, and thus with the ability to model the individual and common knowledge of agents. We have formalized the syntax and semantics of both logics in the interactive theorem prover Lean 4, and used it to prove soundness and completeness of its axiomatization. Our formalization uses the type class system to generalize over different aspects of CLC, thus allowing us to reuse some of to prove properties in related logics such as CL and CLK (CL with individual knowledge).
Cite as

Kai Obendrauf, Anne Baanen, Patrick Koopmann, and Vera Stebletsova. Lean Formalization of Completeness Proof for Coalition Logic with Common Knowledge. In 15th International Conference on Interactive Theorem Proving (ITP 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 309, pp. 28:1-28:18, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{obendrauf_et_al:LIPIcs.ITP.2024.28,
  author =	{Obendrauf, Kai and Baanen, Anne and Koopmann, Patrick and Stebletsova, Vera},
  title =	{{Lean Formalization of Completeness Proof for Coalition Logic with Common Knowledge}},
  booktitle =	{15th International Conference on Interactive Theorem Proving (ITP 2024)},
  pages =	{28:1--28:18},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-337-9},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{309},
  editor =	{Bertot, Yves and Kutsia, Temur and Norrish, Michael},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2024.28},
  URN =		{urn:nbn:de:0030-drops-207560},
  doi =		{10.4230/LIPIcs.ITP.2024.28},
  annote =	{Keywords: Multi-agent systems, Coalition Logic, Epistemic Logic, common knowledge, completeness, formal methods, Lean prover}
}
Document
DOI: 10.4230/LIPIcs.ITP.2024.35
Formal Verification of the Empty Hexagon Number

Authors: Bernardo Subercaseaux, Wojciech Nawrocki, James Gallicchio, Cayden Codel, Mario Carneiro, and Marijn J. H. Heule

Published in: LIPIcs, Volume 309, 15th International Conference on Interactive Theorem Proving (ITP 2024)

Abstract
A recent breakthrough in computer-assisted mathematics showed that every set of 30 points in the plane in general position (i.e., no three points on a common line) contains an empty convex hexagon. Heule and Scheucher solved this problem with a combination of geometric insights and automated reasoning techniques by constructing CNF formulas ϕ_n, with O(n⁴) clauses, such that if ϕ_n is unsatisfiable then every set of n points in general position must contain an empty convex hexagon. An unsatisfiability proof for n = 30 was then found with a SAT solver using 17 300 CPU hours of parallel computation. In this paper, we formalize and verify this result in the Lean theorem prover. Our formalization covers ideas in discrete computational geometry and SAT encoding techniques by introducing a framework that connects geometric objects to propositional assignments. We see this as a key step towards the formal verification of other SAT-based results in geometry, since the abstractions we use have been successfully applied to similar problems. Overall, we hope that our work sets a new standard for the verification of geometry problems relying on extensive computation, and that it increases the trust the mathematical community places in computer-assisted proofs.
Cite as

Bernardo Subercaseaux, Wojciech Nawrocki, James Gallicchio, Cayden Codel, Mario Carneiro, and Marijn J. H. Heule. Formal Verification of the Empty Hexagon Number. In 15th International Conference on Interactive Theorem Proving (ITP 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 309, pp. 35:1-35:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{subercaseaux_et_al:LIPIcs.ITP.2024.35,
  author =	{Subercaseaux, Bernardo and Nawrocki, Wojciech and Gallicchio, James and Codel, Cayden and Carneiro, Mario and Heule, Marijn J. H.},
  title =	{{Formal Verification of the Empty Hexagon Number}},
  booktitle =	{15th International Conference on Interactive Theorem Proving (ITP 2024)},
  pages =	{35:1--35:19},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-337-9},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{309},
  editor =	{Bertot, Yves and Kutsia, Temur and Norrish, Michael},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2024.35},
  URN =		{urn:nbn:de:0030-drops-207633},
  doi =		{10.4230/LIPIcs.ITP.2024.35},
  annote =	{Keywords: Empty Hexagon Number, Discrete Computational Geometry, Erd\H{o}s-Szekeres}
}
Document
DOI: 10.4230/LIPIcs.ITP.2024.37
Integrals Within Integrals: A Formalization of the Gagliardo-Nirenberg-Sobolev Inequality

Authors: Floris van Doorn and Heather Macbeth

Published in: LIPIcs, Volume 309, 15th International Conference on Interactive Theorem Proving (ITP 2024)

Abstract
We introduce an abstraction which allows arguments involving iterated integrals to be formalized conveniently in type-theory-based proof assistants. We call this abstraction the marginal construction, since it is connected to the marginal distribution in probability theory. The marginal construction gracefully handles permutations to the order of integration (Tonelli’s theorem in several variables), as well as arguments involving an induction over dimension. We implement the marginal construction and several applications in the language Lean. The most difficult of these applications, the Gagliardo-Nirenberg-Sobolev inequality, is a foundational result in the theory of elliptic partial differential equations and has not previously been formalized.
Cite as

Floris van Doorn and Heather Macbeth. Integrals Within Integrals: A Formalization of the Gagliardo-Nirenberg-Sobolev Inequality. In 15th International Conference on Interactive Theorem Proving (ITP 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 309, pp. 37:1-37:18, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{vandoorn_et_al:LIPIcs.ITP.2024.37,
  author =	{van Doorn, Floris and Macbeth, Heather},
  title =	{{Integrals Within Integrals: A Formalization of the Gagliardo-Nirenberg-Sobolev Inequality}},
  booktitle =	{15th International Conference on Interactive Theorem Proving (ITP 2024)},
  pages =	{37:1--37:18},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-337-9},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{309},
  editor =	{Bertot, Yves and Kutsia, Temur and Norrish, Michael},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2024.37},
  URN =		{urn:nbn:de:0030-drops-207657},
  doi =		{10.4230/LIPIcs.ITP.2024.37},
  annote =	{Keywords: Sobolev inequality, measure theory, Lean, formalized mathematics}
}
Document
DOI: 10.4230/LIPIcs.TYPES.2023.1
Classification of Covering Spaces and Canonical Change of Basepoint

Authors: Jelle Wemmenhove, Cosmin Manea, and Jim Portegies

Published in: LIPIcs, Volume 303, 29th International Conference on Types for Proofs and Programs (TYPES 2023)

Abstract
Using the language of homotopy type theory (HoTT), we 1) prove a synthetic version of the classification theorem for covering spaces, and 2) explore the existence of canonical change-of-basepoint isomorphisms between homotopy groups. There is some freedom in choosing how to translate concepts from classical algebraic topology into HoTT. The final translations we ended up with are easier to work with than the ones we started with. We discuss some earlier attempts to shed light on this translation process. The proofs are mechanized using the Coq proof assistant and closely follow classical treatments like those by Hatcher [Allen Hatcher, 2002].
Cite as

Jelle Wemmenhove, Cosmin Manea, and Jim Portegies. Classification of Covering Spaces and Canonical Change of Basepoint. In 29th International Conference on Types for Proofs and Programs (TYPES 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 303, pp. 1:1-1:23, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{wemmenhove_et_al:LIPIcs.TYPES.2023.1,
  author =	{Wemmenhove, Jelle and Manea, Cosmin and Portegies, Jim},
  title =	{{Classification of Covering Spaces and Canonical Change of Basepoint}},
  booktitle =	{29th International Conference on Types for Proofs and Programs (TYPES 2023)},
  pages =	{1:1--1:23},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-332-4},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{303},
  editor =	{Kesner, Delia and Reyes, Eduardo Hermo and van den Berg, Benno},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.TYPES.2023.1},
  URN =		{urn:nbn:de:0030-drops-204795},
  doi =		{10.4230/LIPIcs.TYPES.2023.1},
  annote =	{Keywords: Synthetic Homotopy Theory, Homotopy Type Theory, Covering Spaces, Change-of-Basepoint Isomorphism}
}
Document
Invited Talk
DOI: 10.4230/LIPIcs.FSCD.2024.3
Lean: Past, Present, and Future (Invited Talk)

Authors: Sebastian Ullrich

Published in: LIPIcs, Volume 299, 9th International Conference on Formal Structures for Computation and Deduction (FSCD 2024)

Abstract
The Lean programming language and theorem prover project is celebrating its tenth birthday this year, having been started by Leonardo de Moura at Microsoft Research and first release as Lean 0.1 in 2014. In this invited talk, I will review Lean’s history and unique features and discuss our roadmap for its bright future. Corresponding to its major versions ranging from Lean 0.1 to the current version of Lean 4, the focus of the Lean project has evolved over the years. Initially intended as a platform for developing white-box automation, in contrast to the usual black-box approach of stand-alone SMT solvers [de Moura and Passmore, 2013], the system gathered more conventional features of dependently-typed interactive theorem provers as well as an initial crowd of interested mathematicians and computer scientists with its first official release as Lean 2 in 2015 [Leonardo de Moura et al., 2015]. Lean 3 in 2017 introduced user-extensible automation by extending Lean from a specification language to an accessible metaprogramming language [Gabriel Ebner et al., 2017], further accelerating growth of its mathematical library that was spun out into the separate Mathlib project [{The mathlib Community}, 2020]. Spurred by the success but also limitations of this extensibility, we started work on the next version Lean 4 in 2018 [Leonardo de Moura and Sebastian Ullrich, 2021] with the goal of turning Lean into a general-purpose programming language that would allow us to reimplement Lean in Lean itself and thereby make many more aspects of the system user-extensible, in a more efficient manner [Sebastian Ullrich, 2023]. This to date largest rework of Lean’s implementation was completed in 2023 with the official release of Lean 4.0.0, further supporting Mathlib’s growth to more than 1.5 million lines of code at the time of writing as well as improving support for many other applications such as software verification. In 2023, Lean also saw its largest organizational change when Leo and I created the Lean Focused Research Organization (FRO) to bundle and support development of Lean in a dedicated organization for the first time. Thanks to gracious support from philanthropic sponsors, an unprecedented number of currently twelve people now work on the evolution of Lean at the Lean FRO. And there is much left to do: with our new team size, we can now support development on much more than only core features, such as documentation, a robust standard library, and user interfaces and experience as well as a return to the original topic of advanced proof automation. The Lean FRO is committed to ensuring and extending Lean’s applicability in education, research, and industry and to leading it into the next decade of Lean development and beyond.
Cite as

Sebastian Ullrich. Lean: Past, Present, and Future (Invited Talk). In 9th International Conference on Formal Structures for Computation and Deduction (FSCD 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 299, pp. 3:1-3:2, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{ullrich:LIPIcs.FSCD.2024.3,
  author =	{Ullrich, Sebastian},
  title =	{{Lean: Past, Present, and Future}},
  booktitle =	{9th International Conference on Formal Structures for Computation and Deduction (FSCD 2024)},
  pages =	{3:1--3:2},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-323-2},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{299},
  editor =	{Rehof, Jakob},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSCD.2024.3},
  URN =		{urn:nbn:de:0030-drops-203328},
  doi =		{10.4230/LIPIcs.FSCD.2024.3},
  annote =	{Keywords: Lean, interactive theorem proving, focused research organization, history}
}
Document
DOI: 10.4230/LIPIcs.FSCD.2024.22
Automating Boundary Filling in Cubical Agda

Authors: Maximilian Doré, Evan Cavallo, and Anders Mörtberg

Published in: LIPIcs, Volume 299, 9th International Conference on Formal Structures for Computation and Deduction (FSCD 2024)

Abstract
When working in a proof assistant, automation is key to discharging routine proof goals such as equations between algebraic expressions. Homotopy Type Theory allows the user to reason about higher structures, such as topological spaces, using higher inductive types (HITs) and univalence. Cubical Agda is an extension of Agda with computational support for HITs and univalence. A difficulty when working in Cubical Agda is dealing with the complex combinatorics of higher structures, an infinite-dimensional generalisation of equational reasoning. To solve these higher-dimensional equations consists in constructing cubes with specified boundaries. We develop a simplified cubical language in which we isolate and study two automation problems: contortion solving, where we attempt to "contort" a cube to fit a given boundary, and the more general Kan solving, where we search for solutions that involve pasting multiple cubes together. Both problems are difficult in the general case - Kan solving is even undecidable - so we focus on heuristics that perform well on practical examples. We provide a solver for the contortion problem using a reformulation of contortions in terms of poset maps, while we solve Kan problems using constraint satisfaction programming. We have implemented our algorithms in an experimental Haskell solver that can be used to automatically solve goals presented by Cubical Agda. We illustrate this with a case study establishing the Eckmann-Hilton theorem using our solver, as well as various benchmarks - providing the ground for further study of proof automation in cubical type theories.
Cite as

Maximilian Doré, Evan Cavallo, and Anders Mörtberg. Automating Boundary Filling in Cubical Agda. In 9th International Conference on Formal Structures for Computation and Deduction (FSCD 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 299, pp. 22:1-22:18, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{dore_et_al:LIPIcs.FSCD.2024.22,
  author =	{Dor\'{e}, Maximilian and Cavallo, Evan and M\"{o}rtberg, Anders},
  title =	{{Automating Boundary Filling in Cubical Agda}},
  booktitle =	{9th International Conference on Formal Structures for Computation and Deduction (FSCD 2024)},
  pages =	{22:1--22:18},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-323-2},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{299},
  editor =	{Rehof, Jakob},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSCD.2024.22},
  URN =		{urn:nbn:de:0030-drops-203514},
  doi =		{10.4230/LIPIcs.FSCD.2024.22},
  annote =	{Keywords: Cubical Agda, Automated Reasoning, Constraint Satisfaction Programming}
}
Document
DOI: 10.4230/LIPIcs.ITP.2023.15
Closure Properties of General Grammars – Formally Verified

Authors: Martin Dvorak and Jasmin Blanchette

Published in: LIPIcs, Volume 268, 14th International Conference on Interactive Theorem Proving (ITP 2023)

Abstract
We formalized general (i.e., type-0) grammars using the Lean 3 proof assistant. We defined basic notions of rewrite rules and of words derived by a grammar, and used grammars to show closure of the class of type-0 languages under four operations: union, reversal, concatenation, and the Kleene star. The literature mostly focuses on Turing machine arguments, which are possibly more difficult to formalize. For the Kleene star, we could not follow the literature and came up with our own grammar-based construction.
Cite as

Martin Dvorak and Jasmin Blanchette. Closure Properties of General Grammars – Formally Verified. In 14th International Conference on Interactive Theorem Proving (ITP 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 268, pp. 15:1-15:16, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)

Copy BibTex To Clipboard

@InProceedings{dvorak_et_al:LIPIcs.ITP.2023.15,
  author =	{Dvorak, Martin and Blanchette, Jasmin},
  title =	{{Closure Properties of General Grammars – Formally Verified}},
  booktitle =	{14th International Conference on Interactive Theorem Proving (ITP 2023)},
  pages =	{15:1--15:16},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-284-6},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{268},
  editor =	{Naumowicz, Adam and Thiemann, Ren\'{e}},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2023.15},
  URN =		{urn:nbn:de:0030-drops-183906},
  doi =		{10.4230/LIPIcs.ITP.2023.15},
  annote =	{Keywords: Lean, type-0 grammars, recursively enumerable languages, Kleene star}
}
Document
DOI: 10.4230/LIPIcs.ITP.2021.18
Formalized Haar Measure

Authors: Floris van Doorn

Published in: LIPIcs, Volume 193, 12th International Conference on Interactive Theorem Proving (ITP 2021)

Abstract
We describe the formalization of the existence and uniqueness of the Haar measure in the Lean theorem prover. The Haar measure is an invariant regular measure on locally compact groups, and it has not been formalized in a proof assistant before. We will also discuss the measure theory library in Lean’s mathematical library mathlib, and discuss the construction of product measures and the proof of Fubini’s theorem for the Bochner integral.
Cite as

Floris van Doorn. Formalized Haar Measure. In 12th International Conference on Interactive Theorem Proving (ITP 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 193, pp. 18:1-18:17, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)

Copy BibTex To Clipboard

@InProceedings{vandoorn:LIPIcs.ITP.2021.18,
  author =	{van Doorn, Floris},
  title =	{{Formalized Haar Measure}},
  booktitle =	{12th International Conference on Interactive Theorem Proving (ITP 2021)},
  pages =	{18:1--18:17},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-188-7},
  ISSN =	{1868-8969},
  year =	{2021},
  volume =	{193},
  editor =	{Cohen, Liron and Kaliszyk, Cezary},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2021.18},
  URN =		{urn:nbn:de:0030-drops-139139},
  doi =		{10.4230/LIPIcs.ITP.2021.18},
  annote =	{Keywords: Haar measure, measure theory, Bochner integral, Lean, interactive theorem proving, formalized mathematics}
}
Document
DOI: 10.4230/LIPIcs.TYPES.2019.8
Coherence for Monoidal Groupoids in HoTT

Authors: Stefano Piceghello

Published in: LIPIcs, Volume 175, 25th International Conference on Types for Proofs and Programs (TYPES 2019)

Abstract
We present a proof of coherence for monoidal groupoids in homotopy type theory. An important role in the formulation and in the proof of coherence is played by groupoids with a free monoidal structure; these can be represented by 1-truncated higher inductive types, with constructors freely generating their defining objects, natural isomorphisms and commutative diagrams. All results included in this paper have been formalised in the proof assistant Coq.
Cite as

Stefano Piceghello. Coherence for Monoidal Groupoids in HoTT. In 25th International Conference on Types for Proofs and Programs (TYPES 2019). Leibniz International Proceedings in Informatics (LIPIcs), Volume 175, pp. 8:1-8:20, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)

Copy BibTex To Clipboard

@InProceedings{piceghello:LIPIcs.TYPES.2019.8,
  author =	{Piceghello, Stefano},
  title =	{{Coherence for Monoidal Groupoids in HoTT}},
  booktitle =	{25th International Conference on Types for Proofs and Programs (TYPES 2019)},
  pages =	{8:1--8:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-158-0},
  ISSN =	{1868-8969},
  year =	{2020},
  volume =	{175},
  editor =	{Bezem, Marc and Mahboubi, Assia},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.TYPES.2019.8},
  URN =		{urn:nbn:de:0030-drops-130722},
  doi =		{10.4230/LIPIcs.TYPES.2019.8},
  annote =	{Keywords: homotopy type theory, coherence, monoidal categories, groupoids, higher inductive types, formalisation, Coq}
}
Document
DOI: 10.4230/LIPIcs.ITP.2019.19
A Formalization of Forcing and the Unprovability of the Continuum Hypothesis

Authors: Jesse Michael Han and Floris van Doorn

Published in: LIPIcs, Volume 141, 10th International Conference on Interactive Theorem Proving (ITP 2019)

Abstract
We describe a formalization of forcing using Boolean-valued models in the Lean 3 theorem prover, including the fundamental theorem of forcing and a deep embedding of first-order logic with a Boolean-valued soundness theorem. As an application of our framework, we specialize our construction to the Boolean algebra of regular opens of the Cantor space 2^{omega_2 x omega} and formally verify the failure of the continuum hypothesis in the resulting model.
Cite as

Jesse Michael Han and Floris van Doorn. A Formalization of Forcing and the Unprovability of the Continuum Hypothesis. In 10th International Conference on Interactive Theorem Proving (ITP 2019). Leibniz International Proceedings in Informatics (LIPIcs), Volume 141, pp. 19:1-19:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2019)

Copy BibTex To Clipboard

@InProceedings{han_et_al:LIPIcs.ITP.2019.19,
  author =	{Han, Jesse Michael and van Doorn, Floris},
  title =	{{A Formalization of Forcing and the Unprovability of the Continuum Hypothesis}},
  booktitle =	{10th International Conference on Interactive Theorem Proving (ITP 2019)},
  pages =	{19:1--19:19},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-122-1},
  ISSN =	{1868-8969},
  year =	{2019},
  volume =	{141},
  editor =	{Harrison, John and O'Leary, John and Tolmach, Andrew},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2019.19},
  URN =		{urn:nbn:de:0030-drops-110742},
  doi =		{10.4230/LIPIcs.ITP.2019.19},
  annote =	{Keywords: Interactive theorem proving, formal verification, set theory, forcing, independence proofs, continuum hypothesis, Boolean-valued models, Lean}
}
  • Refine by Author
  • 3 van Doorn, Floris
  • 1 Abdulaziz, Mohammad
  • 1 Ammer, Thomas
  • 1 Asgeirsson, Dagur
  • 1 Baanen, Anne
  • Show More...

  • Refine by Classification
  • 6 Theory of computation → Type theory
  • 4 Theory of computation → Logic and verification
  • 2 Mathematics of computing → Algebraic topology
  • 2 Mathematics of computing → Mathematical software
  • 2 Security and privacy → Logic and verification
  • Show More...

  • Refine by Keyword
  • 7 Lean
  • 3 Interactive theorem proving
  • 2 formalized mathematics
  • 2 interactive theorem proving
  • 2 measure theory
  • Show More...

  • Refine by Type
  • 14 document

  • Refine by Publication Year
  • 10 2024
  • 1 2019
  • 1 2020
  • 1 2021
  • 1 2023

Questions / Remarks / Feedback
X

Feedback for Dagstuhl Publishing


Thanks for your feedback!

Feedback submitted

Could not send message

Please try again later or send an E-mail
© 2023-2024 Schloss Dagstuhl – LZI GmbH Imprint Privacy Contact