IT-Dienstleistungen Dr. Thomas Türk
Thomas Tuerk
Dr. Thomas Tuerk
Interactive theorem proving expert

As a freelancer I offer system development and maintenance as well as consulting and training for companies and individuals. My focus is on formal methods, especially interactive theorem proving.


Language Skills

German (native speaker), English (full professional proficiency)

Programming Languages

Haskell, OCaml, SML, Python, Java, C#, Javascript, C++, Bash-Scripte, Perl, PHP, ...

other CS skills

databases (esp. MySQL and MS SQL Server), Git, XML, HTML, CSS, JSON, Docker, ...

Theorem Provers

expert for HOL 4 theorem prover, experienced user of Isabelle/HOL and Coq

Specification and Conformance Testing

experience with model-based-testing, one of the developers of Lem; developer of Adatt; I helped with specifying POSIX filesystems (

Low-Level Code

experience with verification of low level code, e.g. hardering a microhypervisor using Coq or building a transpiler for maschine code; experience with temporal logics and model checking

Program Refinement

I helped develop a program refinement framework in Isabelle/HOL; design of a simple program refinement framework in Coq that was used to harden a micro-hypervisor (;


teaching a master course about interactive theorem proving at KTH in Stockholm (slides)

Curriculum Vitae

Work Experience

Jan. 2022 - ...

Freelancer, IT Dienstleistungen Dr. Thomas Türk, Brechen, Germany.

May 2021 - Oct. 2021

Developer, F+S Fleckner und Simon Informationstechnik GmbH, Limburg, Germany.

Nov. 2017 - April 2021

software developer, et-systems GmbH, Limburg, Germany.

working part time (20 h / week) on customising the ERP System APplus, this involved coding some web-frontend (Javacript, CSS, HTML) in ASP.NET (mainly C#) as well as backend work with an Java application server and a Microsoft SQL server

Nov. 2017 - April 2021

Independent Scholar, Brechen, Germany.

developemnt of ADATT, a tool to help domain-experts write formal specifications

April 2017 - Oct. 2017

Postdoktor, KTH, Stockholm, Sweden.

working for Prof. Dam, giving a course on HOL 4, implementing a transpiler from assembler code to a binary intermediate language in HOL 4

July 2014 - Sep. 2016

Formal Methods Staff Engineer, FireEye, Dresden, Germany.

working on verifying a micro-hypervisor, using program refinement, a formal Coq model and Coq proofs as well as conformance testing

Jan. 2014 - July 2014

Computer Science Engineer, University of Leicester, Leicester, UK.

working with Dr. Tom Ridge on project The future filesystems project; using Lem, I helped to formalise POSIX filesystems and test this formalisation

July 2012 - Jan. 2014

Research Associate, University of Cambridge, Cambridge, UK.

working with Prof. Peter Sewell on project Rigorous Engineering for Mainstream Systems, in particular on tool Lem

May 2011 - July 2012

Wissenschaftlicher Mitarbeiter, TU München, Munich, Germany.

working with Prof. Tobias Nipkow on the CAVA project

Jan. 2010 - Jan. 2011

Research Assistant, University of Cambridge, Cambridge, UK.

working part-time for Matthew Parkinson on separation logic tool JStar while finishing my Ph.D. thesis


Nov. 2002 - April 2011

Ph.D., University of Cambridge, Cambridge, UK.

supervised by Prof. Mike Gordon, thesis title A Separation Logic Framework for HOL; started in parallel with diploma studies in Kaiserslautern under supervision of Prof. Schneider, moved to Cambridge in Jan. 2007

Oct. 1999 - May 2005

Diplom, University of Kaiserslautern, Kaiserslautern, Germany.

supervisor Prof. K. Schneider, thesis title A Hierarchy for Accellera's Property Specification Language betreut von Prof. K. Schneider

1990 - 1999

Abitur (German university entrance qualification), Tilemannschule Limburg, Limburg, Germany.

Contact Details

picture Thomas Tuerk  
Dr. Thomas Tuerk
Albert-Otto-Str. 8
65611 Brechen
phone+49 6483 803150
Personal webpage

I believe that an informal email or a phone call are best suited to get in contact. After initial contact, we can a use other communication channels (like common video conferencing platforms) or meet in person. For existing customers, my Helpdesk might also be useful.

If you are looking for information that is not or only indirectly related to my work as a freelancer, you should have a look at my personal webpage ( You can find personal contact details or a list of my publications there.

Here you can find some selected projects of mine:


Prüfungsplaner is a desktop application used for scheduling oral exams at German high schools, which I have been developing in 2022. Given a list of exams together with information about resources that can be used (rooms, teachers, timeslots, ...) as well as preferences, Prüfungsplaner produces schedules for these exams. A schedule consists of an assignment of a room, a timeslot and teachers to an exam. Using genetic algorithms, Prüfungsplaner attempts to find good schedules quickly. Thereby it is highly non-trivial to define precisely what constitutes a good schedule. Prüfungsplaner is available with and without graphical user-interface for MS Windows and Linux. More details as well as download links of a demo version are available on a separate page. Since Prüfungsplaner is specifically tailored to the needs of German high schools, this separate page as well as Prüfungsplaner itself are only available in German.


I'm interested in simplifying communication between domain experts and formal-methods experts. In order to use interactive theorem proving (ITP) on real world problems, correct and detailled models of real world artifacts like processors or programming languages are needed. Creating such models is a lot of work and the needed details are only known to experts of these real-world systems. Such domain-experts are usually not experts for formal methods or ITP and therefore. Such ITP expertise is however needed to create good formal models. I'm interested in how domain and formal method experts can cooperate to create such formal models.

I got interested in this topic while working for Prof. Peter Sewell on Lem. Lem is a tool for creating portable specifications of real world systems. During the last few years, I have been working on a tool called ADATT. This tool focuses on being comfortably usable by domain experts (poster, talk, current status).

Master Course on Interactive Theorem Proving

In 2017 I gave a master course on Interactive Theorem Proving at KTH focusing on HOL 4. The slides (printer-friendly version, Latex sources) as well as the exercise sheets are available online.


A list of my publications, talks und similar documents can be found on my personal webpage.

Hardening a microhypervisor using Coq in industrie

As part of a commercial formal methods team I helped hardening a microhypervisor using Coq between July 2014 and September 2016.

Impressum - Legal Notifications

The following information (Impressum) is required under German law. This page is also available in German.

Dr. Thomas Tuerk, Dipl.-Inf.

IT Consulting and services: system development and maintenance, consulting and trainings for companies and individuals, main focus on formal methods and interactive theorem proving

Address Dr. Thomas Tuerk
Albert-Otto-Str. 8
65611 Brechen
phone+49 6483 803150
VAT Reg NoDE350366445

Picture Credits

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phone: +49 6483 803150

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