## Miroslaw (Mirek) Truszczynski

### Winner of the Dov Gabbay Prize 2023

University of Kentucky

Miroslaw (Mirek) Truszczynski received his Ph.D. in Mathematics at the Warsaw University of Technology in 1980. In 1984 he joined the Department of Computer Science at the University of Kentucky, where he was promoted to the rank of professor in 1991. In 2013, he was elected Fellow of the Association for the Advancement of Artificial Intelligence (AAAI).

Truszczynski has been a pioneer in knowledge representation and reasoning with seminal contributions to nonmonotonic logic, logic programming and preferential inference, and more than 200 scientific publications. His landmark ACM paper with Victor Marek on autoepistemic logic (1991) brought semantic characterizations of stable extensions as well as algorithms and complexity results. The mathematical research monograph (a rare species) "Nonmonotonic Logic - Context-dependent Reasoning" (1993), which he wrote together with Victor Marek, is rightfully considered a milestone in the development of the field and has inspired generations of logicians in AI. It combines deep foundational insights with conceptual innovations. Another seminal contribution to the theoretical foundations was his work on an algebraic framework for specifying nonmonotonic logics through approximation fixpoint theory (2004).

Truszczynski has also been active in reasoning with preferences, to mention just the important PSPACE completeness result for CP-nets (2008), his work on the combination of logic programming and preferences (2003), or his analysis of set preferences in computational social choice (2019).

On a more practical side, the Default Reasoning System DeReS (1996) he developed together with colleagues was the first serious implementation of Default Logic and paved the way towards practical applications of nonmonotonic reasoning. Truszczynski has also been the inventor of answer set programming (1999), which has become one of the dominant paradigms in declarative problem solving in multiple areas, including decision making, planning, information merging, robotics, and musicology. His work has contributed to a number of successful applications in industry.

Image source: Miroslaw Truszczynski