UNAMBIGUOUS CONSTRAINED AUTOMATA
Michaël Cadilhac, Alain Finkel, Pierre McKenzie · International Journal of Foundations of Computer Science · 2013
The class of languages captured by Constrained Automata (CA) that are unambiguous is shown to possess more closure properties than the provably weaker class captured by deterministic CA. Problems decidable for deterministic CA are nonetheless shown to remain decidable for unambiguous CA, and testing for regularity is added to this set of decidable problems. Unambiguous CA are then shown incomparable with deterministic reversal-bounded machines in terms of expressivity, and a deterministic model equivalent to unambiguous CA is identified.