Person

Viktor Kuncak

Related publications (81)

Mechanized HOL Reasoning in Set Theory

Viktor Kuncak, Simon Guilloud, Sankalp Gambhir

We present a mechanized embedding of higher-order logic (HOL) and algebraic data types (ADTs) into first-order logic with ZFC axioms. Our approach interprets types as sets, with function (arrow) types coinciding with set-theoretic function spaces. We assum ...

2024

Interpolation and Quantifiers in Ortholattices

Viktor Kuncak, Simon Guilloud, Sankalp Gambhir

We study quantifiers and interpolation properties in ortho- logic, a non-distributive weakening of classical logic that is sound for formula validity with respect to classical logic, yet has a quadratic-time decision procedure. We present a sequent-based p ...

2024

Verifying a Realistic Mutable Hash Table: Case Study (Short Paper)

Viktor Kuncak, Samuel Chassot

In this work, we verify, using the Stainless program verifier, the mutable LongMap from the Scala standard library, a hash table using open addressing within a single array. As an executable specification, we write an immutable map based on a list of tuple ...

Springer Science and Business Media Deutschland GmbH2024

Interpolation and Quantifiers in Ortholattices

Viktor Kuncak, Simon Guilloud, Sankalp Gambhir

We study quantifiers and interpolation properties in orthologic, a non-distributive weakening of classical logic that is sound for formula validity with respect to classical logic, yet has a quadratic-time decision procedure. We present a sequent-based pro ...

Springer International Publishing Ag2024

Succinct ordering and aggregation constraints in algebraic array theories

Viktor Kuncak, Rodrigo Raya

We discuss two extensions to a recently introduced theory of arrays, which are based on considerations coming from the model theory of power structures. First, we discuss how the ordering relation on the index set can be expressed succinctly by referring t ...

Elsevier Science Inc2024

Orthologic with Axioms

Viktor Kuncak, Simon Guilloud

We study the proof theory and algorithms for orthologic, a logical system based on ortholattices, which have shown practical relevance in simplification and normalization of verification conditions. Ortholattices weaken Boolean algebras while having polyno ...

Association for Computing Machinery2024

Formula Normalizations in Verification

Viktor Kuncak, Mario Bucev, Simon Guilloud, Dragana Milovancevic

We propose a new approach for normalization and simplification of logical formulas. Our approach is based on algorithms for lattice-like structures. Specifically, we present two efficient algorithms for computing a normal form and deciding the word problem ...

2023

On algebraic array theories

Viktor Kuncak, Rodrigo Raya

Automatic verification of programs manipulating arrays relies on specialised decision procedures. A methodology to classify the theories handled by these procedures is introduced. It is based on decomposition theorems in the style of Feferman and Vaught. T ...

Elsevier Science Inc2023

LISA – A Modern Proof System

Viktor Kuncak, Simon Guilloud, Sankalp Gambhir

We present LISA, a proof system and proof assistant for constructing proofs in schematic first-order logic and axiomatic set theory. The logical kernel of the system is a proof checker for first-order logic with equality and schematic predicate and fun ...

Dagstuhl, Germany, Schloss Dagstuhl - Leibniz-Zentrum fur Informatik2023

Proving and Disproving Equivalence of Functional Programming Assignments

Viktor Kuncak, Dragana Milovancevic

We present an automated approach to verify the correctness of programming assignments, such as the ones that arise in a functional programming course. Our approach takes as input student submissions and reference solutions, and uses equivalence checking to ...

2023

Generalized Arrays for Stainless Frames

Viktor Kuncak, Georg Stefan Schmid

We present an approach for verification of programs with shared mutable references against specifications such as assertions, preconditions, postconditions, and read/write effects. We implement our tool in the Stainless verification system for Scala. A nov ...

Springer, Cham2022

Equivalence Checking for Orthocomplemented Bisemilattices in Log-Linear Time

Viktor Kuncak, Simon Guilloud

We present a quasilinear time algorithm to decide the word problem on a natural algebraic structures we call orthocomplemented bisemilattices, a subtheory of boolean algebra. We use as a base a variation of Hopcroft, Ullman and Aho algorithm for tree isomo ...

Springer2022

Formally Verified Quite OK Image Format

Viktor Kuncak, Mario Bucev

Lossless compression and decompression functions are ubiquitous operations that have a clear high-level specification and are thus suitable as verification benchmarks. Such functions are also important. On the one hand, they improve the performance of comm ...

TU Wien2022

NP Satisfiability for Arrays as Powers

Viktor Kuncak, Rodrigo Raya

We show that the satisfiability problem for the quantifier-free theory of product structures with the equicardinality relation is inNP. As an application, we extend the combinatory array logic fragmentto handle cardinality constraints. The resulting fragme ...

Springer, Cham2022

From Verified Scala to STIX File System Embedded Code Using Stainless

Viktor Kuncak

We present an approach for using formal methods in embedded systems and its evaluation on a case study. In our approach, the developers describe the system in a restricted subset of the high-level programming language Scala. We then use 1) a verification s ...

Springer2022

Zippy LL(1) Parsing with Derivatives

Viktor Kuncak, Romain Edelmann, Jad Hamza

In this paper, we present an efficient, functional, and formally verified parsing algorithm for LL(1) context-free expressions based on the concept of derivatives of formal languages. Parsing with derivatives is an elegant parsing technique, which, in the ...

ASSOC COMPUTING MACHINERY2020

Refutation-based synthesis in SMT

Viktor Kuncak, Andrew Joseph Reynolds

We introduce the first program synthesis engine implemented inside an SMT solver. We present an approach that extracts solution functions from unsatisfiability proofs of the negated form of synthesis conjectures. We also discuss novel counterexample-guided ...

SPRINGER2019

Towards a Compiler for Reals

Viktor Kuncak, Eva Darulova

Numerical software, common in scientific computing or embedded systems, inevitably uses a finite-precision approximation of the real arithmetic in which most algorithms are designed. In many applications, the roundoff errors introduced by finite-precision ...

2017

An Update on Deductive Synthesis and Repair in the Leon Tool

Etienne Kneuss, Viktor Kuncak, Emmanouil Koukoutos

We report our progress in scaling deductive synthesis and repair of recursive functional Scala programs in the Leon tool. We describe new techniques, including a more precise mechanism for encoding the space of meaningful candidate programs. Our techniques ...

2017

Proactive Synthesis of Recursive Tree-to-String Functions from Examples

Viktor Kuncak, Mikaël Mayer, Jad Hamza

Synthesis from examples enables non-expert users to generate programs by specifying examples of their behavior. A domain-specific form of such synthesis has been recently deployed in a widely used spreadsheet software product. In this paper we contribute t ...

2017