English

On the Shuffle Automaton Size for Words

Formal Languages and Automata Theory 2009-07-30 v1 Discrete Mathematics

Abstract

We investigate the state size of DFAs accepting the shuffle of two words. We provide words u and v, such that the minimal DFA for u shuffled with v requires an exponential number of states. We also show some conditions for the words u and v which ensure a quadratic upper bound on the state size of u shuffled with v. Moreover, switching only two letters within one of u or v is enough to trigger the change from quadratic to exponential.

Cite

@article{arxiv.0907.5111,
  title  = {On the Shuffle Automaton Size for Words},
  author = {Franziska Biegler and Mark Daley and Ian McQuillan},
  journal= {arXiv preprint arXiv:0907.5111},
  year   = {2009}
}
R2 v1 2026-06-21T13:30:24.312Z