Introduction to the Special Section on FM 2021

Formal methods have been used in a wide range of domains, including software, cyber-physical systems, and integrated computer-based systems. In recent years, we have seen in particular the application of formal methods in a wide range of areas, such as systems-of-systems, security, artificial intelligence, human-computer interaction, manufacturing, sustainability, power, transport, smart cities, healthcare, and biology. Formal methods also get used more and more in industry. All of these developments are supported by the design and validation of various formal method tools. Formal Methods 2021 (FM 2021) solicited high-quality papers reporting novel research results, as well as tool papers and case study reports. To establish the program of FM 2021, we assembled a program committee of 46 renowned scientists from all over the world. We received a total of 161 abstract submissions, which resulted in 131 full paper submissions from authors in 28 different countries, from which we selected 33 full papers and 2 short tool papers. This special section contains a selection of the best theory papers from the FM 2021 conference that have been selected by the program committee. The articles cover a broad spectrum of topics in the area of formal methods. The six accepted articles include the following: