Complexity of E0L Structural Equivalence

@inproceedings{Salomaa1994ComplexityOE,
  title={Complexity of E0L Structural Equivalence},
  author={Kai Salomaa and Derick Wood and Sheng Yu},
  booktitle={MFCS},
  year={1994}
}
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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References

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TLDR
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TLDR
It is established that some simplification results for E0L grammars that preserve their structure are sufficient to solve the structural equivalence problem, but this does not hold in the context-free case.
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