He is known mostly for his work in logics for multi-agent information flow (-- he was one of the originators of dynamic epistemic logic) and their applications to communication, game theory, quantum computation etc. Between 2001 and 2011 he was a University Lecturer at Oxford University, in the Department of Computer Science. Between 1998 and 2001, he was a post-doctoral researcher at the Dutch Center for Mathematics and Computer Science. He obtained his PhD in Mathematics in 1998 at Indiana University under the supervision of Jon Barwise.