The unit focuses on gaining a deeper understanding of the nature of information and the processes of reasoning and computation. Researchers in the unit are internationally recognised as leading figures on foundational issues in mathematics, theoretical computer science and AI. Foremost, the unit builds on astrong tradition of research in logic in the Netherlands going back to Brouwer, Heyting and Beth. While being best known for our work in intuitionistic and modal logic, we cover most of the classical areas of mathematical logic such as set theory, computability theory, category theory, proof theory and algebraic logic. In theoretical computer science, the unit is famous for its work on coalgebraic and fixed point logics, as well as type theory and the computational content of proofs. In AI, we contribute to the fields of multi-agent systems and formal learning theory. Through its foundational work the unit contributes to neighbouring topics ranging from formal epistemology, decision theory, game theory to cognitive science.