On Determinism and Unambiguity of Weighted Two-way Automata

Vincent Carnino (1) , Sylvain Lombardy (2)

1 LIGM - Laboratoire d'Informatique Gaspard-Monge
2 LaBRI - Laboratoire Bordelais de Recherche en Informatique

In this paper, we first study the conversion of weighted two-way automata to one-way automata. We show that this conversion preserves the unambiguity but does not preserve the determinism. Yet, we prove that the conversion of an unambiguous weighted one-way automaton into a two-way automaton leads to a deterministic two-way automaton. As a consequence, we prove that unambiguous weighted two-way automata are equivalent to deterministic weighted two-way automata in commutative semirings.

Mots clés: Weighted automata; Two-way automata; determinization

Domaines: Mathématique discrète [cs.DM]

Vincent Carnino, Sylvain Lombardy. On Determinism and Unambiguity of Weighted Two-way Automata. 14th International Conference on Automata and Formal Languages, May 2014, Szeged, Hungary. pp.188-200, ⟨10.4204/EPTCS.151.13⟩. ⟨hal-01008785⟩