Logical Definability on Infinite Traces Werner Ebinger and Anca Muscholl Abstract: The main results of this paper are the equivalence of monadic second-order logic and recognizability for real trace languages, and that first-order definable, star-free, and aperiodic real trace languages form the same class of languages. This generalizes results on infinite words and on finite traces to infinite traces. Keywords: Logic in Computer Science, Automata and Formal Languages, Theory of Parallel and Distributed Computation, Theory of Mazurkiewicz Traces, Infinite Computation. @Article{em96, author = "Ebinger, Werner and Muscholl, Anca", title = "Logical definability on infinite traces", journal = TCS, pages = "67-84", volume = "154", year = "1996", annote = "The equivalence of monadic second order definability and recognizability and the equivalence of first order definability, star-freeness, and aperiodicity are generalized to languages of infinite traces.", note = "A preliminary version appeared in "#Pot # "20th " # ICALP # " (ICALP'93), Lund (Sweden) 1993, " # LNCS # " 700, 1993." }