Japaridze, Giorgi - Villanova University, USA. Van Benthem, Johan - University of Amsterdam, the Netherlands and Stanford University, USA. Beklemishev, Lev - Utrecht University, the Netherlands and Steklov Mathematical Institute, Russia. Verbrugge, Rineke - University of Groningen, the Netherlands. Boolos, George - Massachusetts Institute of Technology, USA (Wikipedia article). Guglielmi, Alessio - Technical University of Dresden, Germany.