4 papers
On the Orbits of Automaton Semigroups and Groups
Daniele D'Angeli, Dominik Francoeur, Emanuele Rodaro +1
We investigate the orbits of automaton semigroups and groups to obtain algorithmic and structural results, both for general automata but also for some special subclasses. First, we…
Infinite Automaton Semigroups and Groups Have Infinite Orbits
Daniele D'Angeli, Dominik Francoeur, Emanuele Rodaro +1
We show that an automaton group or semigroup is infinite if and only if it admits an -word (i. e. a right-infinite word) with an infinite orbit, which solves an open problem com…
Orbit Expandability of Automaton Semigroups and Groups
Daniele D'Angeli, Emanuele Rodaro, Jan Philipp Wächter
We introduce the notion of expandability in the context of automaton semigroups and groups: a word is k-expandable if one can append a suffix to it such that the size of the orbit…
On the Structure Theory of Partial Automaton Semigroups
Daniele D'Angeli, Emanuele Rodaro, Jan Philipp Wächter
We study automaton structures, i.e. groups, monoids and semigroups generated by an automaton, which, in this context, means a deterministic finite-state letter-to-letter transducer…