Complexity of E0L Structural Equivalence

@article{Salomaa1995ComplexityOE,
  title={Complexity of E0L Structural Equivalence},
  author={Kai Salomaa and Derick Wood and Sheng Yu},
  journal={RAIRO Theor. Informatics Appl.},
  year={1995},
  volume={29},
  pages={471-485}
}
We show that the EOL structural equivalence problem is logspace hard for deterministic exponential time. Also, we show that this question can be solved in linear space by a synchronized alternating Turing machine, and thus establish an exponential space upper bound for its complexity. The equivalence of finite tree automata is shown to be logspace reducible to context-free structural equivalence. The converse reduction is well known and thus context-free structural equivalence is complete for… 
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