About me

I am a senior researcher at the University of Oslo, associated with the Reliable Systems group and the SIRIUS centre, where I work on formal methods for digital twins, software engineering for and with knowledge graphs, and deductive verification. Before I came to Oslo, I got my PhD from the Technical University of Darmstadt under the supervision of Reiner Hähnle.

My research focuses on the integration of technologies and theories from the Semantic Web with formal methods to specify, analyse and simulate data-heavy computational systems, in particular Digital Twins. I am developing and maintaining the SMOL language which enables programs to use knowledge graphs for reflection and data access. Furthermore, I research novel approaches to modularity in deductive program verification, in particular notions of contracts for distributed and hybrid systems. I am developing and maintaining the Crowbar, a deductive verification system for Active Objects.

I am contributing to the ABS language and am maintaining its variability layer and its hybrid extension HABS.

You can find a list of my publications at dbpl or Google Scholar. Preprints are published here. A short version of my CV can be found here.

Recent and Upcoming Events


The 4th WAKERS workshop on Digital Engineering and Knowledge Representation was held in Stellenbosch, the slides from my tutorial on Semantically lifted digital twins and programs are available here

LNCS 14360

Our state-of-the-art volume on current research trends in Active Object languages is now published by Springer: https://link.springer.com/book/10.1007/978-3-031-51060-1

ABS Workshop’23

The 5th ABS Workshop was held in Lyon, and presented recent results on using trace logics in method contracts and combining type systems with deductive verification of distributed hybrid systems.

Presentation SPLC’23

I presented our work on variability for functional programming and SPLC’23.

Presentation KeY Workshop’23

I presented recent results on using trace logics in method contracts at the 25th KeY Workshop. You can find slides here.

Presentation on Digital Twins for Ecological Systems

I presented an overview over our on-going activities on digital twins for ecological systems at the Green Data Lab Conference. You can find slides and abstract here.

Workshop on Applications of Formal Methods and Digital Twins

The Workshop on Applications of Formal Methods and Digital Twins, was successfully held at FM’23 with 6 exciting presentations and an invited talk by Ana Cavalcanti.

Tutorial on Semantically Reflected Digital Twins

Together with Einar Broch Johnsen, Silvia Lizeth Tapia Tarifa and Rudolf Schlatte, I gave a tutorial at ICTAC 2022 about our work on the combination of Semantic Web technologies with programming languages to enable self-adaptive Digital Twins that react to changes in the asset model.

Recent and Recorded Presentations


An instance of the KalkulierbaR tool for demonstrating different proof calculi is available at kbar.app, the source code to run an own instance is available on github.


I develop, maintain or contribute to the following software. For details, please click on the respective tool.


    Crowbar is a deductive verification tool for ABS, based on heavyweight symbolical execution and behavioral contracts.


    The Semantic Micro Object Language is an object oriented-language that implements semantic lifting: at runtime programs states are interpreted as knowledge graphs and enriched with ontological knowledge.


    KalkulierbaR is a webtool for teaching different proof calculi for predicate and first-order logic.

    Abstract Behavioral Specification (ABS)

    ABS is a language for Abstract Behavioral Specification, which combines implementation-level specifications with verifiability, high-level design with executablity, and formal semantics with practical usability. ABS is a concurrent, object-oriented, modeling language that features functional data-types.


    KeY is a theorem prover for Java Dynamic Logic based on a sequent calculus.