From Regular to Strictly Locally Testable Languages

@article{CrespiReghizzi2012FromRT,
  title={From Regular to Strictly Locally Testable Languages},
  author={Stefano Crespi-Reghizzi and Pierluigi San Pietro},
  journal={Int. J. Found. Comput. Sci.},
  year={2012},
  volume={23},
  pages={1711-1728}
}
A classical result (often credited to Y. Medvedev) states that every language recognized by a finite automaton is the homomorphic image of a local language, over a much larger so-called local alphabet, namely the alphabet of the edges of the transition graph. Local languages are characterized by the value k = 2 of the sliding window width in the McNaughton and Papert's infinite hierarchy of strictly locally testable languages (k-slt). We generalize Medvedev's result in a new direction, studying… 

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