State Complexity of Unranked Tree Automata
Xiaoxue Piao, Kai Salomaa · QSpace (Queen's University Library) · 2010
We consider the representational state complexity of unranked tree automata. The bottom- up computation of an unranked tree automaton may be either deterministic or nondeterministic, and further variants arise depending on whether the horizontal string languages deflning the transitions are represented by a DFA or an NFA. Also, we consider for unranked tree automata the alternative syntactic deflnition of determinism introduced by Cristau et al. We establish upper and lower bounds for the state complexity of conversions between difierent types of unranked tree automata.