Full professor of Computer Science since November 2000. He is serving as dean of the Faculty of Information Engineering, Informatics and Statistics at Sapienza University of Rome. His research interests are in artificial intelligence (AI) and its relationship with databases, theoretical computer science and computer graphics. His main contributions are in the analysis of the computational and semantic properties of the formalisms for commonsense reasoning, with emphasis on non-monotonic reasoning and belief revision. In 1997 he was granted the AI*IA award that is offered by the Italian Association for Artificial Intelligence to the best young researcher in the field of AI. He published over 60 papers, approximately 20 of them on the most prestigious journals of his area. He is member of the editorial board of "Artificial Intelligence Journal" and has been in the editorial board of the "Journal of Artificial Intelligence Research" in the years 1998-1999. He has taken part to several international research projects and has coordinated italian MIUR, CNR and ASI projects. He is currently the coordinator of the Rome unit of the european project MAGICSTER, the FIRB 2001 project ASTRO and a COFIN 2002 and 2004 project. In the period November 2005 till February 2010 he was the President of the Italian Association for Artificial Intelligence (AI*IA).