Lauri Hella, Miikka Vilander. The succinctness of first-order logic over modal logic via a formula size game. In Lev D. Beklemishev, Stéphane Demri, András Maté, editors, Advances in Modal Logic 11, proceedings of the 11th conference on "Advances in Modal Logic," held in Budapest, Hungary, August 30 - September 2, 2016. pages 401-419, College Publications, 2016. [doi]
Abstract is missing.