2017/07/31 by Özlem Salehi, Flavio D'Alessandro, A. C. Cem Say
Computer Science · #cs.FL
paper · pdf · doi:10.4204/eptcs.252.22
published as EPTCS 252, 2017, pp. 234-247 · In Proceedings AFL 2017, arXiv:1708.06226
arxiv created 2017/08/22 · arxiv updated 2017/08/23
We show that some results from the theory of group automata and monoid automata still hold for more general classes of monoids and models. Extending previous work for finite automata over commutative groups, we demonstrate a context-free language that can not be recognized by any rational monoid automaton over a finitely generated permutable monoid. We show that the class of languages recognized by rational monoid automata over finitely generated completely simple or completely 0-simple permutable monoids is a semi-linear full trio. Furthermore, we investigate valence pushdown automata, and prove that they are only as powerful as (finite) valence automata. We observe that certain results proven for monoid automata can be easily lifted to the case of context-free valence grammars.