Keynote at Dutch Formal Methods Day 2024

Marieke Huisman gave a keynote talk titled "VerCors: Inclusive Software Verification" at the Dutch Formal Methods Day 2024.

2nd place of student teams at VerifyThis 2024

The student team "VerCors {P1*P2}" got the second place in the student team category at the 2024 edition of VerifyThis. Congratulations to Pieter Bos and Alexander Stekelenburg for this achievement!

Alexander Stekelenburg and Pieter Bos holding certificates reading Best Student Team - 2nd place - VerCors {P1*P2}

Short Paper acccepted at HCVS Workshop at ETAPS 2024

The short paper Using Horn Solvers to Generate Memory Access Permissions for Deductive Verification – A Preliminary Report by Lukas Armborst and Marieke Huisman has been accepted at the HCVS workshop at ETAPS.

VerCors Poster & Tool Demo at ETAPS 2024

At ETAPS, VerCors will be presented as a poster and during the tool demo session on Wednesday April 10, 14:00 – 16:00. Come and talk to us if you are interested to learn more about VerCors.

Lorentz workshop on Contract Languages

Several VerCors team members participated in the Lorentz workshop on Contract Languages, March 4 – 8 at the Lorentz center in Leiden.A group photo of the participants of the Lorentz workshop.

Paper accepted at RRRR Workshop at ETAPS

The paper Replication of a Deductive Synthesizer for Programs with Pointers written by Serge Johanns and Marieke Huisman has been accepted the RRRR workshop at ETAPS.

New PhD candidate Alexander Stekelenburg

From this February, Alexander Stekelenburg has joined our VerCors team as a PhD candidate. Alexander will also be working under the Pallas project for the program analysis for LLVM-IR and all its source languages. Welcome Alexander!

New PhD candidate Robert Mensing

From this January, Robert Mensing has joined our VerCors team as a PhD candidate. Robert will be working under the Pallas project for the program analysis for LLVM-IR and all its source languages. Welcome Robert!

Journal Paper accepted at JSS

The paper Survey of Annotation Generators for Deductive Verifiers written by Sophie Lathouwers and Marieke Huisman has been accepted to be published in the journal of Systems & Software.

Member graduation: Ellen Wittingen

One of our ex-master students, Ellen Wittingen, has graduated today. Her mastersthesis is titled "Deductive verification for SYCL". You can find it here. Well done Ellen! We wish you best of luck in your future endeavors.

Prof. Marieke Huisman receives the 2023 Athena Award

Prof. Marieke Huisman has been awarded the 2023 Athena Award. The Athena Award rewards female researchers who stand out, and because of that are role models for others, demonstrating that a career in science is possible. Congratulations, Marieke!

A new VerCors project: Pallas

Pallas (Program Analysis for LLVM-IR and All its Source languages) is a new project involving VerCors. Pallas aims for a universal approach to ensure correctness in programming languages based on LLVM, simplifying verification tech development. This is crucial given software's pivotal role in our lives, where failures can lead to disasters and financial losses. Software developers urgently seek techniques to improve quality, especially formal verification to prevent errors. Pallas tackles integration challenges by creating deductive program verification for LLVM-IR, applicable to any programming language that compiles to this format.

Marieke Huisman to talk at iFM PhD Symposium

Marieke Huisman will give an invited talk at the iFM PhD Symposium. The title of her presentation is "A verification journey: from sequential Java programs to massively-parallel GPU code".

Marieke Huisman appointed NAE fellow

Prof. Marieke Huisman has been appointed as one of 62 fellows for the Netherlands Academy of Engineering. The fellowship is awarded to members who stand out in terms of achievements, societal impact and leadership. Congratulations, Marieke!

PhD defense of Sophie Lathouwers

The former VerCors team member Sophie Lathouwers successfully defended her PhD thesis on the 17th of October 2023. Congratulations, Doctor Sophie Lathouwers!

Paper accepted at VMCAI

The paper "Deductive Verification of Parameterized Embedded Systems modeled in SystemC" by Philip Tasche, Raúl E. Monti, Stefanie Eva Drerup, Pauline Blohm, Paula Herber and Marieke Huisman has been accepted at VMCAI 2024. The artifact has also been evaluated and granted the Available and Reusable badges.

Paper accepted at iFM

The paper "Joining Forces! Reusing Contracts for Deductive Verifiers through Automatic Translation" by Lukas Armborst, Sophie Lathouwers and Marieke Huisman, has been accepted at iFM 2023. The corresponding artifact has also been successfully checked for all three badges: Functional, Reusable and Available.

Member graduation: Dré van Oorschot

One of our ex-master students, Dré van Oorschot, has graduated today. His mastersthesis is titled "VCLLVM: A Transformation Tool for LLVM IR programs to aid Deductive Verification". You can find it here. Well done Dré! We wish you best of luck in your future endeavors.

Member graduation: Joël Ledelay

One of our ex-master students, Joël Ledelay, has graduated today. His mastersthesis is titled "Verification of distributed locks: a case study". You can find it here. Well done Joël! We wish you best of luck in your future endeavors.

Recent presentations at PLACES and ABZ

Marieke Huisman gave a talk titled "VerCors & Alpinist: Verification of Optimised GPU Programs" at the PLACES workshop, co-located at ETAPS, and at the ABZ conference. This talk is based on earlier work done in a collaboration between Ömer Şakar, Mohsen Safari, Marieke Huisman, and Anton Wijs, and can be found here.

Member goodbye: Raúl E. Monti

Today the VerCors team, and FMT as a whole, organized a goodbye party for Raúl E. Monti. Raúl joined the VerCors team on the 3rd of June 2019, and has since then successfully helped us maintain and further develop the VerCors toolset. Raúl's next challenge will be in Veldhoven at ASML. We thank you for your contributions, Raúl, and wish you best of luck at ASML!

VerCors 2.0 Released

VerCors 2.0.0 has been released, and can be obtained here.

Member graduation: Jan Boerman

One of our ex-master students, Jan Boerman, has graduated today. His mastersthesis is titled "Formal verification of a sequential SCC algorithm". You can find it here. Congratulations Jan!

Paper published on Multiparty Session Typing & VerCors

We wish to congratulate Jelle Bouma, Stijn de Gouw and Sung-Shik Jongmans with publishing their paper at TACAS 2023. It is titled "Multiparty Session Typing in Java, Deductively", and it presents the BGJ tool, which checks adherence of Java code to a multiparty session type with near-zero overhead. It accomplishes this by generating contracts that encode this protocol, which can then be verified with VerCors. A preprint can be found on Sung-Shik's website:

Paper published

The paper "The Integration of Testing and Program Verification", by Petra van den Bos and Marieke Huisman, has been published in "A Journey from Process Algebra via Timed Automata to Model Learning. Essays Dedicated to Frits Vaandrager on the Occasion of His 60th Birthday".

Paper accepted at ETAPS

The paper "JavaBIP meets VerCors: Towards the Safety of Concurrent Software Systems in Java" by Simon Bliudze, Petra van den Bos, Marieke Huisman, Robert Rubbens, and Larisa Safina, has been accepted at FASE 2023.

Paper presented at ISOLA 2022

Robert Rubbens presented the paper "On Deductive Verification of an Industrial Concurrent Software Component with VerCors", by Raul E. Monti; Robert Rubbens and Marieke Huisman, at the ISOLA conference 2022, in Greece.

PhD defense of Mohsen Safari

Our former VerCors team member Mohsen Safari successfully defended his PhD thesis last 6th of July. Congratulations doctor Mohsen Safari! Mohsen will now continue his carrier as an HPC Consultant at SURF.

Mohsen Safari PhD defense

New team member

Naum Tomov has joined our team as a scientific programmer. We now have 2 scientific programmers to tackle the issues in our tool :D

2nd place at VerifyThis 2022

Our team "VerCors team Yellow" got the second place prize at this year's VerifyThis competition! Congratulations Robert Rubbens and Phillip Tasche for your achievement.

Bob Rubbens and Philip Tasche holding certificates reading VerifyThis 2nd place - VerCors Yellow

VerCors present at this year's VerifyThis competition

The VerCors team will bring 3 teams to compete at this year's edition of the VerifyThis competition taking part in the opening weekend (2nd and 3rd of April) of the ETAPS conferences in Munich.

Journal paper accepted at TCS

The paper Formal verification of parallel prefix sum and stream compaction algorithms in CUDA by Mohsen Safari and Marieke Huisman, was accepted to be published in the journal for Theoretical Computer Science . Here is the link to the paper.

Paper accepted at FormaliSE

The paper Formal Specifications Investigated: A Classification and Analysis of Annotations for Deductive Verifiers by Sophie Lathouwers and Marieke Huisman, was accepted at the 10th International Conference on Formal Methods in Software Engineering (FormaliSE 2022).

New PhD candidate Philip Tasche

From last January, Philip Tasche has joined our VerCors team as a PhD candidate. Philip will be working under the SAVES project for the formal verification of SystemC embedded systems software. Welcome Philip!

Paper accepted at ESOP 2022

The paper A Predicate Transformer for Choreographies by Sung-Shik Jongmans and Petra van den Bos, was accepted at the 31st European Symposium on Programming (ESOP 2022).

Paper accepted at TACAS 2022

The paper Alpinist: an Annotation-Aware GPU Program Optimizer by Ömer Şakar, Mohsen Safari, Marieke Huisman and Anton Wijs, was accepted at the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems (TACAS 2022).

Petra van den Bos started as assistant professor in Twente

Our team member Petra van den Bos started as an assistant professor at the our group! She is interested in applying formal techniques to determine the (in)correctness of software systems. In particular, her research interests include deductive verification and model-based testing.

Paper accepted at FMICS 2021

The paper Modular Transformation of Java Exceptions Modulo Errors by Robert Rubbens, Sophie Lathouwers and Marieke Huisman, was accepted at the International Conference on Formal Methods for Industrial Critical Systems (FMICS 2021). Here is the link to the paper.

New internship to bring VerCors a nice UI

Théophile Petit from TELECOM Nancy has joined our VerCors team for an internship during this summer period. He will be working on a VS-code compatible plugin for VerCors.

Paper accepted at SAS 2021

The paper Automated Verification of the Parallel Bellman–Ford Algorithm by M. Safari, W. Oortwijn and M. Huisman, has been accepted at the 28th Static Analysis Symposium.

Paper accepted at FormaliSE 2021

Permission-Based Verification of Red-Black Trees and Their Merging by Lukas Armborst and Marieke Huisman has been accepted at the 2021 edition of FormaliSE.

1st prize at Versen PhD Thesis Award 2021

Wytse's thesis "Deductive techniques for model-based concurrency verification" gets the 1st prize at the Versen PhD thesis Award 2021.

Book cover of Deductive Techniques for Model-Based Concurrency Verification by Wytse Oortwijn

New VerCors project SAVES

SAVES: Scalable Verification of Industrial Control Systems is a new project involving VerCors. This project is a cooperation of WWU-Münster and the University of Twente, funded by a WWU - UT collaboration grant. The project aims to formaly analyse embedded systems developed with the C++ library System-C using VerCors.

Two new papers around VerCors accepted!

Our papers Mohsen Safari and Marieke Huisman - Formal Verification of Parallel Stream Compaction and Summed-Area Table Algorithms, and Stefan Blom, Saeed Darabi, Marieke Huisman and Mohsen Safari - Correct Program Parallelisation were accepted in ICTAC 2020 and the STTT journal respectively.

Two papers on VerCors accepted at iFM 2020!!!

Our papers Mohsen Safari and Marieke Huisman - A Generic Approach to the Verification of the Permutation Property of Sequential and Parallel Swap-based Sorting Algorithms, and Lars van den Haak, Anton Wijs, Mark van den Brand and Marieke Huisman - Formal methods for GPGPU programming: is the demand met? were accepted in iFM 2020. Moreover, the latest paper is our first ChEOPS project paper.

Members Graduation!

Two of our ex-master students, Bob Rubbens and Ömer Şakar, have recently graduated (see here and here ) and have decided to join the VerCors team as PhD candidates in the Mercedes project and ChEOPS project respectively. Nice that we have managed to keep them with us!

New PhD Student in Mercedes Project

From 1st of March, Lukas Armborst is our new PhD student working on the Mercedes project.

Paper accepted at NFM

Formal Verification of Parallel Prefix Sum written by Mohsen, Wytse, Sebastiaan and Marieke has been accepted for this year edition of NFM .

Paper accepted at TACAS 2020

Automated Verification of Parallel Nested DFS written by Wytse, Marieke, Sebastiaan and Jaco has been accepted for this years edition of TACAS.

Best paper award at IFM 2019

The paper Practical Abstractions for Automated Verification of Message Passing Concurrency written by Wytse Oortwijn and Marieke Huisman got the best paper award at IFM 2019 conference .

Wytse Oortwijn holding IFM best paper award certificate.

Welcome Petra to the VerCors team!

From February 1st, Petra van den Bos has joined our team as a PostDoc under the Mercedes Project. Petra finished her PhD studies at the Institute for Computing and Information Sciences of the Radboud University in Nijmegen, the Netherlands, under the supervision of Jan Tretmans and Frits Vaandrager. During her work she focussed on topics around model-based testing. However, she also enjoys working on other topics inside formal methods and we are very happy to have her working along us and improving VerCors.

2019 VerCors team picture

On the occasion of Wytse Oortwijn’s PhD defence, a big part of the VerCors (former and current) team members got reunited. We were able to take this very nice picture together:

VerCors members

May 2020 bring even more people into our picture!

Marieke Huisman talked about software reliability at KNAW

Prof. Marieke Huisman, leader of the FMT group and the VerCors team, was one of the speakers at a public symposium called Verificatie van software: erg complex maar in ieders belang (Software verification: very complex but in everyone's interest) at the Koninklijke Nederlandse Akademie van Wetenschappen.

She gave an overview of the area of deductive program verification, and how VerCors contributes to this area. Here’s an impression of the evening. A recording of the symposium will be made available via TXT radio.

Wytse Oortwijn's PHD thesis defence: December 12

Wytse Oortwijn PHD thesis defence is approaching

Wytse has contributed to VerCors for several years, during his PhD projects in the FMT group under the supervision of Prof Marieke Huisman. He will be defending his thesis, entitled "Deductive Techniques for Model-Based Concurrency Verification" on Thursday 12th of December, 16:30 to 18:00 at Waaier, 4-G, Berkhoffzaal, University of Twente. For an introduction to his thesis and more information about the defence follow this link.

FMT member Sophie Lathouwers wins the Greenhost prize of the Koninklijke Hollandsche Maatschappij der Wetenschappen

Sophie Lathouwers has won the Greenhost prize of the Koninklijke Hollandsche Maatschappij der Wetenschappen with her Master thesis "Reasoning About the Correctness of Sanitizers."

The prize is in the category of Internet & Technical Sciences, it is awarded through the KHMW (Royal Dutch Institute of Sciences), and sponsored by Greenhost. The prize-giving ceremony will take place on Thursday November 7 next at 15:00 in Amsterdam (REC, room C0.01, Nieuwe Achtergracht 166). There, Sophie will give a short presentation on her work. For more information visit here .

New VerCors related work

Anton Wijs and Maciej Wiłkowski present a paper involving VerCors at SEFM 2019

In Modular Indirect Push-Button Formal Verification of Multi-threaded Code Generators, Anton Wijs and Maciej Wiłkowski use VerCors to assist the verification of automated code generation of multi-threaded programs for model-driven development.

Two papers accepted at iFM 2019

Two papers written by Wytse Oortwijn and Marieke Huisman have been accepted in this year's edition of iFM.

"Practical Abstractions for Automated Verification of Message Passing Concurrency" presenting a new technique which integrates model based verification and code verification for message passing programs and "Formal Verification of an Industrial Safety-Critical Traffic Tunnel Control System", a case study in the use of VerCors in a critical industrial system, have been accepted at the 15th International Conference on integrated Formal Methods taking place between the 2nd and the 6th of December this year, at Bergen, Norway.

Blind Henk Mulder now receives a master degree

On July 10th, 2019, Henk Mulder got his Master degree at University of Twente.

Henk Mulder did his Master Thesis at the Formal Methods and Tools group, on identifying and solving bottlenecks in the VerCors tool, under the supervision of Marieke Huisman. The VerCors toolset can be used to verify memory safety and functional correctness of concurrent and parallel programs. By encoding the problem into an intermediate language the power of existing tools is leveraged to support additional concurrency models. However, for certain programs verification takes significant time. Thanks to the work of Henk Mulder, we now know why, and more importantly, what we can do about it.

Thesis document

Henk Mulder got a 9 for his Master project, and graduated Cum laude. Our congratulations go out to Henk Mulder, on this great accomplishment!

VERCORS Advisory Board Meeting

An advisory board meeting of VerCors was held in University of Twente on June 6, 2019. VerCors Team elaborated main tool features with the board members from different industrial organizations.

The board members include people from BetterBe , Thales group, Rosen group, Polder Valley and Technolution.

The board members have shown a deep interest in the tool and gave valuable feedback to make the VerCors tool more applicable and efficient for industrial projects.

New PostDoc in Mercedes Project

Raúl E. Monti joined VerCors Team and started as a PostDoc on the Mercedes project.

NWO OTP grant for ChEOPS (verified Construction of corrEct and Optimised Parallel Software) Project

Prof.dr. Marieke Huisman and dr. Anton Wijs received an NWO OTP grant for the project “ChEOPS: verified Construction of corrEct and Optimised Parallel Software”.

Two PhD students will be appointed, one in Twente and one in Eindhoven, to make the development and maintenance of software aimed at graphics processing units (GPUs) more insightful and effective in terms of functional correctness and performance.

GPUs have an increasingly big impact on industry and academia, due to their great computational capabilities. However, in practice, one usually needs to have expert knowledge on GPU architectures to optimally gain advantage of those capabilities. At the Eindhoven University of Technology, Wijs will work on modelling GPU applications using a Domain Specific Language, formally verifying the correctness of the models, and automatically generating GPU code. At the University of Twente, Huisman will work on the structured optimisation of GPU code, while ensuring that functional correctness is preserved. Existing formal verification techniques, model checking and code verification, will be combined to create, for the first time, a complete end-to-end development workflow for GPU applications.

To ensure the practical effectiveness of the resulting workflow, a users committee, consisting of SURFsara, the Netherlands eScience Center, Stream HPC, and CodePlay (UK), will provide real-life cases and provide feedback throughout the project.


VerCors Team participated in ETAPS 2019 conference for VerifyThis competition, held in Parague and have won two awards.

Sophie Lathouwers and Wytse Oortwijn won the Best Student Team award!

Marieke Huisman and Sebastiaan Joosten won the “Most Distinguished Tool Feature Award” for their usage of ghost method parameters to model sparse matrices!

New PhD Candidate in Mercedes

Sophie Lathouwers started as a PhD student on the Mercedes project. Sophie will investigate the automated generation of auxiliary annotations, which are needed for program verification in VerCors.

Towards Reliable Concurrent Software

During the symposium organised for the 60th birthday of Arnd Poetzsch-Heffter, Marieke Huisman presented a position paper "Towards Reliable Concurrent Software", co-authored with Sebastiaan Joosten, which outlines the plans of the Mercedes project.

ISoLA 2018

ISOLA 2018 features several presentations around VerCors.

Marieke Huisman presents the position paper "On Models and Code - A Unified Approach to Support Large-Scale Deductive Program Verification".

In this paper, she argues that we need a seamless transition between models and code, and she sketches how the VerCors tool provides a first step towards this goal.

Marieke Huisman also presented the paper Program Correctness by Transformation, co-authored by Stefan Blom, Saeed Darabi and Mohsen Safari, which describes how the VerCors tool can be used to ensure that program transformations and optimisations preserve program correctness.

Finally, Sebastiaan Joosten presented Static Code Verification Through Process Models, co-authored by Marieke Huisman, which sketches an alternative approach for the use of abstractions to reason about concurrent software.

New Master Student

Minh Nguyen starts his final Master thesis project, in which he will try to verify functional correctness of a red black tree using VerCors.

Marieke Huisman, Stefan Blom (BetterBe) and Sebastiaan Joosten will supervise the project.

FTfFP 2018

The workshop FTfFP 2018 (@ECOOP 2018) features several VerCors related presentations. Wytse Oortwijn gives a tool demo of the VerCors tool set, while Sebastiaan Joosten presents the paper An Exercise in Verifying Sequential Programs with VerCors, co-authored by Wytse Oortwijn, Mohsen Safari and Marieke Huisman.

In this paper, we present our solutions to two of the VerifyThis 2018 challenges.

VerifyThis 2018

Two VerCors teams participated in this year's VerifyThis program verification competition, held in Thessaloniki as part of ETAPS 2018.

Wytse Oortwijn and Mohsen Safari won the 2nd prize for the best student team.

New PhD Students in Mercedes Project

Two new PhD students started on the Mercedes project: Mohsen Safari and Fauzia Ehsan.

Mohsen's project will contribute to further improvement of the verification of GPU programs in VerCors. Fauzia's project will focus on the effective use of abstractions to reason about concurrent or distributed programs, using VerCors.

Marieke Huisman Inaugural Lecture

Marieke Huisman gives her inaugural lecture, entitled "Software Reliability for Everyone".

In this lecture, she presents her view on the future of software verification research.

Booklet inaugural lecture