Unary NFAs with Limited Nondeterminism

Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8327)


We consider unary finite automata employing limited nondeterminism. We show that for a unary regular language, a minimal finite tree width nondeterministic finite automaton (NFA) can always be found in Chrobak normal form. A similar property holds with respect to other measures of nondeterminism. The latter observation is used to establish relationships between classes of unary regular languages recognized by NFAs of given size where the nondeterminism is limited in various ways. Finally, we show that the branching measure of a unary NFA is always either bounded by a constant or has an exponential growth rate.


finite automata limited nondeterminism state complexity unary regular languages 


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© Springer International Publishing Switzerland 2014

Authors and Affiliations

  1. 1.School of ComputingQueen’s UniversityKingstonCanada

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