Mitja Kulczynski

Mitja Kulczynski, Axel Legay, Dirk Nowotka et al.

In recent years there has been a considerable effort in optimising formal methods for application to code. This has been driven by tools such as CPAChecker, DIVINE, and CBMC. At the same time tools such as Uppaal have been massively expanding the realm of more traditional model checking technologies to include strategy synthesis algorithms - an aspect becoming more and more needed as software becomes increasingly parallel. Instead of reimplementing the advances made by Uppaal in this area, we suggest in this paper to develop a bridge between the source code and the engine of Uppaal. Our approach uses the widespread intermediate language LLVM and makes recent advances of the Uppaal ecosystem readily available to analysis of source code.

Pamela Fleischmann, Mitja Kulczynski, Dirk Nowotka

When unexpected incidents occur, new innovative and flexible solutions are required. If this event is something such radical and dramatic like the COVID-19 pandemic, these solutions must aim to guarantee as much normality as possible while protecting lives. After a moment of shock our university decided that the students have to be able to pursue their studies for guaranteeing a degree in the expected time since most of them faced immediate financial problems due to the loss of their student jobs. This implied, for us as teachers, that we had to reorganise not only the teaching methods from nearly one day to the next, but we also had to come up with an adjusted way of examinations which had to take place in person with pen and paper under strict hygiene rules. On the other hand the correction should avoid personal contacts. We developed a framework which allowed us to correct the digitalised exams safely at home while providing the high standards given by the general data protection regulation of our country. Moreover, the time spent in the offices could be reduced to a minimum thanks to automatically generated exam sheets, automatically re-digitalised and sorted worked-on exams.

Murphy Berzish, Joel D. Day, Vijay Ganesh et al.

Widespread use of string solvers in formal analysis of string-heavy programs has led to a growing demand for more efficient and reliable techniques which can be applied in this context, especially for real-world cases. Designing an algorithm for the (generally undecidable) satisfiability problem for systems of string constraints requires a thorough understanding of the structure of constraints present in the targeted cases. In this paper, we investigate benchmarks presented in the literature containing regular expression membership predicates, extract different first order logic theories, and prove their decidability, resp. undecidability. Notably, the most common theories in real-world benchmarks are PSPACE-complete and directly lead to the implementation of a more efficient algorithm to solving string constraints.