Friday April 24, Falak Sher successfully defended his PhD dissertation, entitled “Abstraction and Refinement of Probabilistic Automata using Modal Stochastic Games” for a jury consisting of Lijun Zhang (ISCAS Beijing, China), Stefan Kowalewski, Erich Grädel, and Joost-Pieter Katoen (all Aachen).  Falak’s dissertation is concerned with game-based abstraction-refinement in which (instead of existing works) the underlying correctness notion is based on distribution-based (rather than state-based) simulation relations.