ON THE FINITENESS PROBLEM FOR AUTOMATON (SEMI)GROUPS
Ali Akhavi, Ines Klimann, Sylvain Lombardy, Jean Mairesse, Matthieu Picantin · International Journal of Algebra and Computation · 2012
This paper addresses a decision problem highlighted by Grigorchuk, Nekrashevich, and Sushchanskiĭ, namely the finiteness problem for automaton (semi)groups. For semigroups, we give an effective sufficient but not necessary condition for finiteness and, for groups, an effective necessary but not sufficient condition. The efficiency of the new criteria is demonstrated by testing all Mealy automata with small stateset and alphabet. Finally, for groups, we provide a necessary and sufficient condition that does not directly lead to a decision procedure.