23 Search Results for "Yang, Hongseok"


Document
A Convenient Fibration for Dependently-Typed Probability Theory

Authors: Danel Ahman, Ohad Kammar, and Rasmus Ejlers Møgelberg

Published in: LIPIcs, Volume 380, 41st Annual Symposium on Logic in Computer Science (LICS 2026)


Abstract
We describe semantic structures relevant for interpreting dependent types for statistical and probabilistic modelling. Our development extends the theory of quasi-Borel spaces (qbses) of Staton et. al, which support simply-typed, higher-order probability theory with continuous distributions. It is well-known that qbses can interpret a dependent-type theory supporting dependent function-spaces through the codomain fibration. We define an equivalent split fibration based on the family fibration, which we call quasi-Borel families (qbfs), characterise its structure, equip it with fibred monads of measures and probability, and use them to develop dependently-typed probability theory. We characterise the structure of the qbf fibration that is relevant for dependently-typed probability theory in elementary form. Our characterisations include: context extension, dependent pairs, dependent functions, extensional identity types, fibred products and coproducts, subspaces, a universe of propositions, and straightforward internalisation and externalisation principles for discrete spaces. We use these concepts to define fibred distribution and probability monads, the semantic structure needed to interpret probability distributions under a dependent context. We show that this structure satisfies a fibred version of Kock’s synthetic measure theory. We also use these concepts to develop a qbs counterpart to Kolmogorov’s conditional expectation. Our main result is a version of the conditional expectation that, under standard regularity assumptions, is measurable in both the random variables we are conditioning, and the observation map we are conditioning by.

Cite as

Danel Ahman, Ohad Kammar, and Rasmus Ejlers Møgelberg. A Convenient Fibration for Dependently-Typed Probability Theory. In 41st Annual Symposium on Logic in Computer Science (LICS 2026). Leibniz International Proceedings in Informatics (LIPIcs), Volume 380, pp. 4:1-4:27, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)


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@InProceedings{ahman_et_al:LIPIcs.LICS.2026.4,
  author =	{Ahman, Danel and Kammar, Ohad and M{\o}gelberg, Rasmus Ejlers},
  title =	{{A Convenient Fibration for Dependently-Typed Probability Theory}},
  booktitle =	{41st Annual Symposium on Logic in Computer Science (LICS 2026)},
  pages =	{4:1--4:27},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-434-5},
  ISSN =	{1868-8969},
  year =	{2026},
  volume =	{380},
  editor =	{Faggian, Claudia and Katoen, Joost-Pieter},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.LICS.2026.4},
  URN =		{urn:nbn:de:0030-drops-267915},
  doi =		{10.4230/LIPIcs.LICS.2026.4},
  annote =	{Keywords: probability theory, quasi-Borel space, Grothendieck fibration, fibred monad, conditional expectation, measure theory, random variables, dependent types, quasitopos, probabilistic programming, denotational semantics, synthetic measure theory}
}
Document
Interpreting Lambda Calculus in Domain-Valued Random Variables

Authors: Robert Furber, Radu Mardare, Prakash Panangaden, and Dana Scott

Published in: LIPIcs, Volume 363, 34th EACSL Annual Conference on Computer Science Logic (CSL 2026)


Abstract
We develop Boolean-valued domain theory and show how the lambda-calculus can be interpreted using domain-valued random variables. We focus on the reflexive domain construction rather than the language and its semantics. We develop the Boolean-valued set theory needed from scratch and then develop Boolean-valued domain theory on top of that. The notions of equality and partial order have to be given Boolean-valued interpretations; when we say that an equation is valid in the model we mean that its interpretation is the top element of the Boolean algebra.

Cite as

Robert Furber, Radu Mardare, Prakash Panangaden, and Dana Scott. Interpreting Lambda Calculus in Domain-Valued Random Variables. In 34th EACSL Annual Conference on Computer Science Logic (CSL 2026). Leibniz International Proceedings in Informatics (LIPIcs), Volume 363, pp. 48:1-48:20, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)


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@InProceedings{furber_et_al:LIPIcs.CSL.2026.48,
  author =	{Furber, Robert and Mardare, Radu and Panangaden, Prakash and Scott, Dana},
  title =	{{Interpreting Lambda Calculus in Domain-Valued Random Variables}},
  booktitle =	{34th EACSL Annual Conference on Computer Science Logic (CSL 2026)},
  pages =	{48:1--48:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-411-6},
  ISSN =	{1868-8969},
  year =	{2026},
  volume =	{363},
  editor =	{Guerrini, Stefano and K\"{o}nig, Barbara},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CSL.2026.48},
  URN =		{urn:nbn:de:0030-drops-254734},
  doi =		{10.4230/LIPIcs.CSL.2026.48},
  annote =	{Keywords: lambda calculus, domain theory, random variables}
}
Document
On the Entailment Problem in Dynamic Separation Logic with Inductive Definitions

Authors: Nicolas Peltier

Published in: LIPIcs, Volume 363, 34th EACSL Annual Conference on Computer Science Logic (CSL 2026)


Abstract
Separation Logic (SL) is a well-established framework for reasoning about programs that manipulate dynamic memory. To express and verify properties of custom recursive data structures, SL is extended with spatial predicates defined by user-specified inductive rules. Many verification problems reduce to deciding entailments between formulas involving these predicates. While the general entailment problem is undecidable, a broad class of inductive rules - known as PCE (Progressing, Connected, and Established) - has been identified for which entailment is decidable. In this work, we extend the study of the entailment problem to Dynamic Separation Logic (DSL), an extension of SL that includes dynamic modalities for reasoning about actions on the heap and store. We show that entailment in DSL remains decidable for PCE rules by proving that dynamic modalities can be automatically eliminated.

Cite as

Nicolas Peltier. On the Entailment Problem in Dynamic Separation Logic with Inductive Definitions. In 34th EACSL Annual Conference on Computer Science Logic (CSL 2026). Leibniz International Proceedings in Informatics (LIPIcs), Volume 363, pp. 16:1-16:20, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)


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@InProceedings{peltier:LIPIcs.CSL.2026.16,
  author =	{Peltier, Nicolas},
  title =	{{On the Entailment Problem in Dynamic Separation Logic with Inductive Definitions}},
  booktitle =	{34th EACSL Annual Conference on Computer Science Logic (CSL 2026)},
  pages =	{16:1--16:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-411-6},
  ISSN =	{1868-8969},
  year =	{2026},
  volume =	{363},
  editor =	{Guerrini, Stefano and K\"{o}nig, Barbara},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CSL.2026.16},
  URN =		{urn:nbn:de:0030-drops-254402},
  doi =		{10.4230/LIPIcs.CSL.2026.16},
  annote =	{Keywords: Separation logic, Dynamic logic, Entailment problem}
}
Document
Invited Paper
Rational Lawvere Logic (Invited Paper)

Authors: Giorgio Bacci, Radu Mardare, Prakash Panangaden, and Gordon Plotkin

Published in: LIPIcs, Volume 363, 34th EACSL Annual Conference on Computer Science Logic (CSL 2026)


Abstract
We study Rational Lawvere logic (RL). This logic is defined over the extended positive reals with an algebraic structure combining the Lawvere quantale (with the reversed order on the extended reals and a sum as tensor) and a multiplicative quantale (with the usual order on the extended reals and a multiplication as tensor); together they provide a semiring structure. The logic is designed for complex quantitative reasoning, including sequents expressing inequalities between rational functions over the extended positive reals. We give a deduction system and demonstrate its expressiveness by deriving a classical result from probability theory relating the Kantorovich and total variation distances. Our deductive system is complete for finitely axiomatizable theories. The proof of completeness relies on the Krivine-Stengle Positivstellensatz. We additionally provide complexity results for both RL and its affine fragment AL. We consider two decision problems: the satisfiability of a set of sequents and whether a sequent follows from a finite set of sequent. We show that both problems lie in PSPACE for RL, and we give sharper complexity bounds for AL: the first problem is NP-complete, while the second is co-NP-complete.

Cite as

Giorgio Bacci, Radu Mardare, Prakash Panangaden, and Gordon Plotkin. Rational Lawvere Logic (Invited Paper). In 34th EACSL Annual Conference on Computer Science Logic (CSL 2026). Leibniz International Proceedings in Informatics (LIPIcs), Volume 363, pp. 3:1-3:21, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)


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@InProceedings{bacci_et_al:LIPIcs.CSL.2026.3,
  author =	{Bacci, Giorgio and Mardare, Radu and Panangaden, Prakash and Plotkin, Gordon},
  title =	{{Rational Lawvere Logic}},
  booktitle =	{34th EACSL Annual Conference on Computer Science Logic (CSL 2026)},
  pages =	{3:1--3:21},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-411-6},
  ISSN =	{1868-8969},
  year =	{2026},
  volume =	{363},
  editor =	{Guerrini, Stefano and K\"{o}nig, Barbara},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CSL.2026.3},
  URN =		{urn:nbn:de:0030-drops-254277},
  doi =		{10.4230/LIPIcs.CSL.2026.3},
  annote =	{Keywords: Quantitative reasoning, complete deductive system, Lawvere’s quantale}
}
Document
Iterating Non-Aggregative Structure Compositions

Authors: Marius Bozga, Radu Iosif, and Florian Zuleger

Published in: LIPIcs, Volume 360, 45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025)


Abstract
An aggregative composition is a binary operation obeying the principle that the whole is determined by the sum of its parts. The development of graph algebras, on which the theory of formal graph languages is built, relies on aggregative compositions that behave like disjoint union, except for a set of well-marked interface vertices from both sides, that are joined. The same style of composition has been considered in the context of relational structures, that generalize graphs and use constant symbols to label the interface. In this paper, we study a non-aggregative composition operation, called fusion, that joins non-deterministically chosen elements from disjoint structures. The sets of structures obtained by iteratively applying fusion do not always have bounded tree-width, even when starting from a tree-width bounded set. First, we prove that the problem of the existence of a bound on the tree-width of the closure of a given set under fusion is decidable, when the input set is described inductively by a finite hyperedge-replacement (HR) grammar, written using the operations of aggregative composition, forgetting and renaming of constants. Such sets are usually called context-free. Second, assuming that the closure under fusion of a context-free set has bounded tree-width, we show that it is the language of an effectively constructible HR grammar. A possible application of the latter result is the possiblity of checking whether all structures from a non-aggregatively closed set having bounded tree-width satisfy a given monadic second order logic formula.

Cite as

Marius Bozga, Radu Iosif, and Florian Zuleger. Iterating Non-Aggregative Structure Compositions. In 45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 360, pp. 18:1-18:18, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{bozga_et_al:LIPIcs.FSTTCS.2025.18,
  author =	{Bozga, Marius and Iosif, Radu and Zuleger, Florian},
  title =	{{Iterating Non-Aggregative Structure Compositions}},
  booktitle =	{45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025)},
  pages =	{18:1--18:18},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-406-2},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{360},
  editor =	{Aiswarya, C. and Mehta, Ruta and Roy, Subhajit},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSTTCS.2025.18},
  URN =		{urn:nbn:de:0030-drops-250997},
  doi =		{10.4230/LIPIcs.FSTTCS.2025.18},
  annote =	{Keywords: Hyperedge replacement, Tree-width}
}
Document
Nondeterministic Asynchronous Dataflow in Isabelle/HOL

Authors: Rafael Castro Gonçalves Silva, Laouen Fernet, and Dmitriy Traytel

Published in: LIPIcs, Volume 352, 16th International Conference on Interactive Theorem Proving (ITP 2025)


Abstract
We formalize nondeterministic asynchronous dataflow networks in Isabelle/HOL. Dataflow networks are comprised of operators that are capable of communicating with the network, performing silent computations, and making nondeterministic choices. We represent operators using a shallow embedding as codatatypes. Using this representation, we define standard asynchronous dataflow primitives, including sequential and parallel composition and a feedback operator. These primitives adhere to a number of laws from the literature, which we prove by coinduction using weak bisimilarity as our equality. Albeit coinductive and nondeterministic, our model is executable via code extraction to Haskell.

Cite as

Rafael Castro Gonçalves Silva, Laouen Fernet, and Dmitriy Traytel. Nondeterministic Asynchronous Dataflow in Isabelle/HOL. In 16th International Conference on Interactive Theorem Proving (ITP 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 352, pp. 30:1-30:20, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{silva_et_al:LIPIcs.ITP.2025.30,
  author =	{Silva, Rafael Castro Gon\c{c}alves and Fernet, Laouen and Traytel, Dmitriy},
  title =	{{Nondeterministic Asynchronous Dataflow in Isabelle/HOL}},
  booktitle =	{16th International Conference on Interactive Theorem Proving (ITP 2025)},
  pages =	{30:1--30:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-396-6},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{352},
  editor =	{Forster, Yannick and Keller, Chantal},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2025.30},
  URN =		{urn:nbn:de:0030-drops-246280},
  doi =		{10.4230/LIPIcs.ITP.2025.30},
  annote =	{Keywords: dataflow, verification, coinduction, Isabelle/HOL}
}
Document
Certified Implementability of Global Multiparty Protocols

Authors: Elaine Li and Thomas Wies

Published in: LIPIcs, Volume 352, 16th International Conference on Interactive Theorem Proving (ITP 2025)


Abstract
Implementability is the decision problem at the heart of top-down approaches to protocol verification. In this paper, we present a mechanization of a recently proposed precise implementability characterization by Li et al. for a large class of protocols that subsumes many existing formalisms in the literature. Our protocols and implementations model asynchronous commmunication, and can exhibit infinite behavior. We improve upon their pen-and-paper results by unifying distinct formalisms, simplifying existing proof arguments, elaborating on the construction of canonical implementations, and even uncovering a subtle bug in the semantics for infinite words. As a corollary of our mechanization, we show that the original characterization of implementability applies even to protocols with infinitely many participants. We also contribute a reusable library for reasoning about generic communicating state machines. Our mechanization consists of about 15k lines of Rocq code. We believe that our mechanization can provide the foundation for deductively proving the implementability of protocols beyond the reach of prior work, extracting certified implementations for finite protocols, and investigating implementability under alternative asynchronous communication models.

Cite as

Elaine Li and Thomas Wies. Certified Implementability of Global Multiparty Protocols. In 16th International Conference on Interactive Theorem Proving (ITP 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 352, pp. 15:1-15:20, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{li_et_al:LIPIcs.ITP.2025.15,
  author =	{Li, Elaine and Wies, Thomas},
  title =	{{Certified Implementability of Global Multiparty Protocols}},
  booktitle =	{16th International Conference on Interactive Theorem Proving (ITP 2025)},
  pages =	{15:1--15:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-396-6},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{352},
  editor =	{Forster, Yannick and Keller, Chantal},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITP.2025.15},
  URN =		{urn:nbn:de:0030-drops-246139},
  doi =		{10.4230/LIPIcs.ITP.2025.15},
  annote =	{Keywords: Asynchronous protocols, communicating state machines, labeled transition systems, infinite semantics, realizability, multiparty session types, choreographies, deadlock freedom}
}
Document
On the Reachability Problem for Two-Dimensional Branching VASS

Authors: Clotilde Bizière, Thibault Hilaire, Jérôme Leroux, and Grégoire Sutre

Published in: LIPIcs, Volume 345, 50th International Symposium on Mathematical Foundations of Computer Science (MFCS 2025)


Abstract
Vectors addition systems with states (VASS), or equivalently Petri nets, are arguably one of the most studied formalisms for the modeling and analysis of concurrent systems. A central decision problem for VASS is reachability: whether there exists a run from an initial configuration to a final one. This problem has been known to be decidable for over forty years, and its complexity has recently been precisely characterized. Our work concerns the reachability problem for BVASS, a branching generalization of VASS. In dimension one, the exact complexity of this problem is known. In this paper, we prove that the reachability problem for 2-dimensional BVASS is decidable. In fact, we even show that the reachability set admits a computable semilinear presentation. The decidability status of the reachability problem for BVASS remains open in higher dimensions.

Cite as

Clotilde Bizière, Thibault Hilaire, Jérôme Leroux, and Grégoire Sutre. On the Reachability Problem for Two-Dimensional Branching VASS. In 50th International Symposium on Mathematical Foundations of Computer Science (MFCS 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 345, pp. 22:1-22:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{biziere_et_al:LIPIcs.MFCS.2025.22,
  author =	{Bizi\`{e}re, Clotilde and Hilaire, Thibault and Leroux, J\'{e}r\^{o}me and Sutre, Gr\'{e}goire},
  title =	{{On the Reachability Problem for Two-Dimensional Branching VASS}},
  booktitle =	{50th International Symposium on Mathematical Foundations of Computer Science (MFCS 2025)},
  pages =	{22:1--22:19},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-388-1},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{345},
  editor =	{Gawrychowski, Pawe{\l} and Mazowiecki, Filip and Skrzypczak, Micha{\l}},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2025.22},
  URN =		{urn:nbn:de:0030-drops-241294},
  doi =		{10.4230/LIPIcs.MFCS.2025.22},
  annote =	{Keywords: Vector addition systems, Reachability problem, Semilinear sets, Verification}
}
Document
A Sound and Complete Characterization of Fair Asynchronous Session Subtyping

Authors: Mario Bravetti, Luca Padovani, and Gianluigi Zavattaro

Published in: LIPIcs, Volume 348, 36th International Conference on Concurrency Theory (CONCUR 2025)


Abstract
Session types are abstractions of communication protocols enabling the static analysis of message-passing processes. Refinement notions for session types are key to support safe forms of process substitution while preserving their compatibility with the rest of the system. Recently, a fair refinement relation for asynchronous session types has been defined allowing the anticipation of message outputs with respect to an unbounded number of message inputs. This refinement is useful to capture common patterns in communication protocols that take advantage of asynchrony. However, while the semantic (à la testing) definition of such refinement is straightforward, its characterization has proved to be quite challenging. In fact, only a sound but not complete characterization is known so far. In this paper we close this open problem by presenting a sound and complete characterization of asynchronous fair refinement for session types. We relate this characterization to those given in the literature for synchronous session types by leveraging a novel labelled transition system of session types that embeds their asynchronous semantics.

Cite as

Mario Bravetti, Luca Padovani, and Gianluigi Zavattaro. A Sound and Complete Characterization of Fair Asynchronous Session Subtyping. In 36th International Conference on Concurrency Theory (CONCUR 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 348, pp. 11:1-11:17, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{bravetti_et_al:LIPIcs.CONCUR.2025.11,
  author =	{Bravetti, Mario and Padovani, Luca and Zavattaro, Gianluigi},
  title =	{{A Sound and Complete Characterization of Fair Asynchronous Session Subtyping}},
  booktitle =	{36th International Conference on Concurrency Theory (CONCUR 2025)},
  pages =	{11:1--11:17},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-389-8},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{348},
  editor =	{Bouyer, Patricia and van de Pol, Jaco},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CONCUR.2025.11},
  URN =		{urn:nbn:de:0030-drops-239615},
  doi =		{10.4230/LIPIcs.CONCUR.2025.11},
  annote =	{Keywords: Binary sessions, session types, fair asynchronous subtyping}
}
Document
Cancellative Convex Semilattices

Authors: Ana Sokolova and Harald Woracek

Published in: LIPIcs, Volume 342, 11th Conference on Algebra and Coalgebra in Computer Science (CALCO 2025)


Abstract
Convex semilattices are algebras that are at the same time a convex algebra and a semilattice, together with a distributivity axiom. These algebras have attracted some attention in the last years as suitable algebras for probability and nondeterminism, in particular by being the Eilenberg-Moore algebras of the nonempty finitely-generated convex subsets of the distributions monad. A convex semilattice is cancellative if the underlying convex algebra is cancellative. Cancellative convex algebras have been characterized by M. H. Stone and by H. Kneser: A convex algebra is cancellative if and only if it is isomorphic to a convex subset of a vector space (with canonical convex algebra operations). We prove an analogous theorem for convex semilattices: A convex semilattice is cancellative if and only if it is isomorphic to a convex subset of a Riesz space, i.e., a lattice-ordered vector space (with canonical convex semilattice operations).

Cite as

Ana Sokolova and Harald Woracek. Cancellative Convex Semilattices. In 11th Conference on Algebra and Coalgebra in Computer Science (CALCO 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 342, pp. 12:1-12:15, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{sokolova_et_al:LIPIcs.CALCO.2025.12,
  author =	{Sokolova, Ana and Woracek, Harald},
  title =	{{Cancellative Convex Semilattices}},
  booktitle =	{11th Conference on Algebra and Coalgebra in Computer Science (CALCO 2025)},
  pages =	{12:1--12:15},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-383-6},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{342},
  editor =	{C\^{i}rstea, Corina and Knapp, Alexander},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CALCO.2025.12},
  URN =		{urn:nbn:de:0030-drops-235714},
  doi =		{10.4230/LIPIcs.CALCO.2025.12},
  annote =	{Keywords: convex semilattice, cancellativity, Riesz space}
}
Document
Solving Guarded Domain Equations in Presheaves over Ordinals and Mechanizing It

Authors: Sergei Stepanenko and Amin Timany

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


Abstract
Constructing solutions to recursive domain equations is a well-known, important problem in the study of programs and programming languages. Mathematically speaking, the problem is finding a fixed point (up to isomorphism) of a suitable functor over a suitable category. A particularly useful instance, inspired by the step-indexing technique, is where the functor is over (a subcategory of) the category of presheaves over the ordinal ω and the functors are locally-contractive, also known as guarded functors. This corresponds to step-indexing over natural numbers. However, for certain problems, e.g., when dealing with infinite non-determinism, one needs to employ trans-finite step-indexing, i.e., consider presheaf categories over higher ordinals. Prior work on trans-finite step-indexing either only considers a very narrow class of functors over a particularly restricted subcategory of presheaves over higher ordinals, or treats the problem very generally working with sheaves over an arbitrary complete Heyting algebra with a well-founded basis. In this paper we present a solution to the guarded domain equations problem over all guarded functors over the category of presheaves over ordinal numbers, as well as its mechanization in the Rocq Prover. As the categories of sheaves and presheaves over ordinals are equivalent, our main contribution is simplifying prior work from the setting of the category of sheaves to the setting of the category of presheaves and mechanizing it - presheaves are more amenable to mechanization in a proof assistant.

Cite as

Sergei Stepanenko and Amin Timany. Solving Guarded Domain Equations in Presheaves over Ordinals and Mechanizing It. In 10th International Conference on Formal Structures for Computation and Deduction (FSCD 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 337, pp. 33:1-33:24, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{stepanenko_et_al:LIPIcs.FSCD.2025.33,
  author =	{Stepanenko, Sergei and Timany, Amin},
  title =	{{Solving Guarded Domain Equations in Presheaves over Ordinals and Mechanizing It}},
  booktitle =	{10th International Conference on Formal Structures for Computation and Deduction (FSCD 2025)},
  pages =	{33:1--33:24},
  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.2025.33},
  URN =		{urn:nbn:de:0030-drops-236486},
  doi =		{10.4230/LIPIcs.FSCD.2025.33},
  annote =	{Keywords: Domain Equations, Guarded Fixed Points, Fixed Points, Category Theory, Rocq, Presheaves, Ordinals}
}
Document
Reusing Caches and Invariants for Efficient and Sound Incremental Static Analysis

Authors: Mamy Razafintsialonina, David Bühler, Antoine Miné, Valentin Perrelle, and Julien Signoles

Published in: LIPIcs, Volume 333, 39th European Conference on Object-Oriented Programming (ECOOP 2025)


Abstract
Static analysis by means of abstract interpretation is a tool of choice for proving absence of some classes of errors, typically undefined behaviors in C code, in a sound way. However, static analysis tools are hardly integrated in CI/CD processes. One of the main reasons is that they are still time- and memory-expensive to apply after every single patch when developing a program. For solving this issue, incremental static analysis helps developers quickly obtain analysis results after making changes to a program. However, existing approaches are often not guaranteed to be sound, limited to specific analyses, or tied to specific tools. This limits their generalizability and applicability in practice, especially for large and critical software. In this paper, we propose a generic, sound approach to incremental static analysis that is applicable to any abstract interpreter. Our approach leverages the similarity between two versions of a program to soundly reuse previously computed analysis results. We introduce novel methods for summarizing functions and reusing loop invariants. They significantly reduce the cost of reanalysis, while maintaining soundness and a high level of precision. We have formalized our approach, proved it sound, implemented it in Eva, the abstract interpreter of Frama-C, and evaluated it on a set of real-world commits of open-source programs.

Cite as

Mamy Razafintsialonina, David Bühler, Antoine Miné, Valentin Perrelle, and Julien Signoles. Reusing Caches and Invariants for Efficient and Sound Incremental Static Analysis. In 39th European Conference on Object-Oriented Programming (ECOOP 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 333, pp. 28:1-28:29, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{razafintsialonina_et_al:LIPIcs.ECOOP.2025.28,
  author =	{Razafintsialonina, Mamy and B\"{u}hler, David and Min\'{e}, Antoine and Perrelle, Valentin and Signoles, Julien},
  title =	{{Reusing Caches and Invariants for Efficient and Sound Incremental Static Analysis}},
  booktitle =	{39th European Conference on Object-Oriented Programming (ECOOP 2025)},
  pages =	{28:1--28:29},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-373-7},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{333},
  editor =	{Aldrich, Jonathan and Silva, Alexandra},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECOOP.2025.28},
  URN =		{urn:nbn:de:0030-drops-233207},
  doi =		{10.4230/LIPIcs.ECOOP.2025.28},
  annote =	{Keywords: Abstract Interpretation, Static Analysis, Incremental Analysis}
}
Document
Ensuring Convergence and Invariants Without Coordination

Authors: Dina Borrego, Nuno Preguiça, Elisa Gonzalez Boix, and Carla Ferreira

Published in: LIPIcs, Volume 333, 39th European Conference on Object-Oriented Programming (ECOOP 2025)


Abstract
The CAP theorem demonstrates a trade-off between consistency and availability (and, by extension, latency) in systems where network partitions are unavoidable, such as in cloud computing and local-first software. While adopting weak consistency can preserve availability, it may result in inconsistencies that compromise application correctness. Replicated data types provide a principled, coordination-free approach to guarantee convergence but do not consider application invariants. Existing methods for maintaining invariants in replicated systems either rely on coordination - undermining the benefits of weak consistency - or suffer from limited applicability. This paper introduces the No-Op framework, a generic approach for enforcing consistency without coordination while guaranteeing both convergence and invariant preservation. The core idea of the No-Op approach is to resolve conflicts among concurrent operations by prioritising one operation over the other according to programmer-defined conflict resolution policies. This prioritisation transforms the less-preferred operation into a no-side-effect operation, ensuring conflict-free execution. We formalise the model underlying the No-Op framework and introduce a replication protocol built upon it, accompanied by a formal proof of correctness for both the framework and the protocol. Furthermore, we demonstrate the framework’s applicability by showcasing the design of widely used replicated data types and the preservation of a wide range of application invariants.

Cite as

Dina Borrego, Nuno Preguiça, Elisa Gonzalez Boix, and Carla Ferreira. Ensuring Convergence and Invariants Without Coordination. In 39th European Conference on Object-Oriented Programming (ECOOP 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 333, pp. 4:1-4:29, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{borrego_et_al:LIPIcs.ECOOP.2025.4,
  author =	{Borrego, Dina and Pregui\c{c}a, Nuno and Gonzalez Boix, Elisa and Ferreira, Carla},
  title =	{{Ensuring Convergence and Invariants Without Coordination}},
  booktitle =	{39th European Conference on Object-Oriented Programming (ECOOP 2025)},
  pages =	{4:1--4:29},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-373-7},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{333},
  editor =	{Aldrich, Jonathan and Silva, Alexandra},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECOOP.2025.4},
  URN =		{urn:nbn:de:0030-drops-232978},
  doi =		{10.4230/LIPIcs.ECOOP.2025.4},
  annote =	{Keywords: distributed systems, conflict resolution, RDTs, invariant preservation}
}
Document
Fair Termination of Asynchronous Binary Sessions

Authors: Luca Padovani and Gianluigi Zavattaro

Published in: LIPIcs, Volume 333, 39th European Conference on Object-Oriented Programming (ECOOP 2025)


Abstract
We study a theory of asynchronous session types ensuring that well-typed processes terminate under a suitable fairness assumption. Fair termination entails starvation freedom and orphan message freedom namely that all messages, including those that are produced early taking advantage of asynchrony, are eventually consumed. The theory is based on a novel fair asynchronous subtyping relation for session types that is coarser than the existing ones. The type system is also the first of its kind that is firmly rooted in linear logic: fair asynchronous subtyping is incorporated as a natural generalization of the cut and axiom rules of linear logic and asynchronous communication is modeled through a suitable set of commuting conversions and of deep cut reductions in linear logic proofs.

Cite as

Luca Padovani and Gianluigi Zavattaro. Fair Termination of Asynchronous Binary Sessions. In 39th European Conference on Object-Oriented Programming (ECOOP 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 333, pp. 24:1-24:29, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{padovani_et_al:LIPIcs.ECOOP.2025.24,
  author =	{Padovani, Luca and Zavattaro, Gianluigi},
  title =	{{Fair Termination of Asynchronous Binary Sessions}},
  booktitle =	{39th European Conference on Object-Oriented Programming (ECOOP 2025)},
  pages =	{24:1--24:29},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-373-7},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{333},
  editor =	{Aldrich, Jonathan and Silva, Alexandra},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECOOP.2025.24},
  URN =		{urn:nbn:de:0030-drops-233169},
  doi =		{10.4230/LIPIcs.ECOOP.2025.24},
  annote =	{Keywords: Binary sessions, fair asynchronous subtyping, fair termination, linear logic}
}
Document
Bottom-Up Synthesis of Memory Mutations with Separation Logic

Authors: Kasra Ferdowsi and Hila Peleg

Published in: LIPIcs, Volume 333, 39th European Conference on Object-Oriented Programming (ECOOP 2025)


Abstract
Programming-by-Example (PBE) is the paradigm of program synthesis specified via input-output pairs. It is commonly used because examples are easy to provide and collect from the environment. A popular optimization for enumerative synthesis with examples is Observational Equivalence (OE), which groups programs into equivalence classes according to their evaluation on example inputs. Current formulations of OE, however, are severely limited by the assumption that the synthesizer’s target language contains only pure components with no side-effects, either enforcing this in their target language, or ignoring it, leading to an incorrect enumeration. This limits their ability to use realistic component sets. We address this limitation by borrowing from Separation Logic, which can compositionally reason about heap mutations. We reformulate PBE using a restricted Separation Logic: Concrete Heap Separation Logic (CHSL), transforming the search for programs into a proof search in CHSL. This lets us perform bottom-up enumerative synthesis without the need for expert-provided annotations or domain-specific inferences, but with three key advantages: we (i) preserve correctness in the presence of memory-mutating operations, (ii) compact the search space by representing many concrete programs as one under CHSL, and (iii) perform a provably correct OE-reduction. We present SObEq (Side-effects in OBservational EQuivalence), a bottom-up enumerative algorithm that, given a PBE task, searches for its CHSL derivation. The SObEq algorithm is proved correct with no purity assumptions: we show it is guaranteed to lose no solutions. We also evaluate our implementation of SObEq on benchmarks from the literature and online sources, and show that it produces high-quality results quickly.

Cite as

Kasra Ferdowsi and Hila Peleg. Bottom-Up Synthesis of Memory Mutations with Separation Logic. In 39th European Conference on Object-Oriented Programming (ECOOP 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 333, pp. 10:1-10:32, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


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@InProceedings{ferdowsi_et_al:LIPIcs.ECOOP.2025.10,
  author =	{Ferdowsi, Kasra and Peleg, Hila},
  title =	{{Bottom-Up Synthesis of Memory Mutations with Separation Logic}},
  booktitle =	{39th European Conference on Object-Oriented Programming (ECOOP 2025)},
  pages =	{10:1--10:32},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-373-7},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{333},
  editor =	{Aldrich, Jonathan and Silva, Alexandra},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECOOP.2025.10},
  URN =		{urn:nbn:de:0030-drops-233036},
  doi =		{10.4230/LIPIcs.ECOOP.2025.10},
  annote =	{Keywords: Program synthesis, observational equivalence}
}
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